CAGED - the good, the bad and the ugly?

BillDL

I think that whenever something is given a snappy acronym or pidgeon-holed into a "system" it can often infer that it is an entirely new system of doing something, when in fact many of us may well have already been using or at least visualising the CAGED system long before we heard of it.

When I think back to 1979/80 when I had a plywood nylon strung guitar, a couple of chord books, and cassettes and records to try and play along with, I can still recall how my discovery stages went.

At the time I was mostly playing "open" chords, so to match the key of the radio, cassettes or records I used a capo.  The chord books I had showed a bunch of chord inversions of a major chord in one key mapped out on a full-length fretboard, and it did this for all the keys laid out side-by side so you could see the groupings of notes going up one fret at a time as you worked your way from left to right and flipped through the book.  The inversions of the C major chord were followed by those for the C#/Db major, then D major, and so on, so it was quite visual.

Between looking at the chord books and using a capo it didn't take me very long to notice how the open 2nd, 3rd and 4th strings of an open G chord correlated with the fretted notes on those strings 2 frets higher to form the Open A chord shape.  Similarly striking was how the point of the triangle formed by the Open D shape on the 2nd string was the first finger position of the open C chord moved up 2 frets.  While looking at how the first finger took the place of the nut for barre chords and when using a capo I noticed from the Root 6 (open E shape) G Major barre chord how the 1st and 6th string notes were both on the 3rd fret, so if I switched fingering and moved up a fret and now barred the previously open strings with my first finger I had a movable (but almost impossible to play) G# chord based on the open G shape.  I began to see these overlapping groups of notes.

I armed myself with different coloured pens and circled these note groupings to make it even more visual.  I still have those original chord books with all the coloured circles and notes made alongside them with arrows pointing to adjacent charts.  I still didn't know instinctively where the 3rd and 5th notes of the chords lay for each of the inversions and shapes (nor the actual notes they made) without having to count up from a known note, but it quickly occurred to me how a full chord contains duplicated notes and I therefore didn't have to play all the notes.  I didn't realise at the time that I had been seeing triads but had been playing full chords.  When I realised this I discovered that I could play triads and chord fragments quite quickly and in close proximity on the neck by simply knowing the root note of the particular shapes.

When I later had a steel string guitar and had learned a few bass string riffs and simple melodies, then acquired some literature that showed the Major Pentatonic, Minor Pentatonic and "Blues" scales in various keys, I started to see how the riffs and melodies fitted both the scales and the chords formed from them.  The biggest revelation was when I was able to start bending into and then sliding between the different major pentatonic scale shapes and I began to hear the target notes I wanted to hear from the chords lying beneath them.

That probably all took about 9 months to a year, and from the start I had been using the CAGED system without realising it.  I only heard the expression CAGED about 15 years ago after having played up to a reasonably advanced intermediate level over 25 years (although there were numerous lengthy "dry" periods in between).  I suppose that giving a "system" of learning a name or acronym condenses the theory surrounding it into a manageable and systematic process, but I would suspect that, like me, a great many people have been using the principles for a long time without knowing what "CAGED" actually was.

viz

^ exactly. That’s what I picked up from Kelpbeds’s (extremely good) video. Nice playing too by the way. And all that stuff I knew, I just called it “not skipping about the fretboard if you don’t need to”. 

I guess what I’d, probably wrongly, previously thought, was that it was an ideal lens through which to understand inversions. Whereas I found it totally confusing because it’s like looking at them through the wrong end of the telescope. 

As a result of Kelpbeds’s comprehensive overview, I have at last found peace with CAGED

merlin

Who rattled my CAGED?

kelpbeds

viz said:

^ exactly. That’s what I picked up from Kelpbeds’s (extremely good) video. Nice playing too by the way. And all that stuff I knew, I just called it “not skipping about the fretboard if you don’t need to”. 

I guess what I’d, probably wrongly, previously thought, was that it was an ideal lens through which to understand inversions. Whereas I found it totally confusing because it’s like looking at them through the wrong end of the telescope. 

As a result of Kelpbeds’s comprehensive overview, I have at last found peace with CAGED

Ah cheers Viz, very much appreciated coming from a theory maestro like yourself!

Ddigger

Roland said:

GuyBoden said:

CAGED is exactly what it says on the tin, A CAGE for your playing, once in the CAGE, escaping from the CAGE is difficult.

Surely you are joking Mr Feynman?

I guess he takes lemon and milk in his tea! 

guitarjack66

kelpbeds said:

I think one of the big issues with CAGED is that most people don't understand it in it's entirety. People understand bits of it (and then think they know the whole system) and then talk about it's shortcomings, not realising that it is actually a lot more comprehensive than they realise. CAGED encompasses different chordal voicing, a whole range of arpeggios, pentatonic scales, major and minor scales and modes. It's a way of putting different layers on the same concept rather than having different systems to deal with each concept. I decided to tackle all of this by producing a video which explains CAGED here.

I am going to have to dig into this a bit more,especially being able to play in certain sections of the fretboard. I still dont know all of the string inversions yet but my scale understanding is certainly improving and caged has helped this too.
You are very knowledgeable and talented my friend. You have now got a sub from me.

GuyBoden

Quotes from some Jazzers:

"As far as I'm aware, L.A-based session guitarist, Jack Marshall came up with the name 'CAGED' around 1950."

"it just wasn't called CAGED. Joe Pass was the first person I heard call it CAGED. (He called it that for teaching purposes; it wasn't called that when he learned it.)"

"Once upon a time someone asked Jimmy Bruno about "CAGED" fingerings and he went ballistic.
The fingerings are the same but that's not where Jimmy got them (-the "CAGED system" is fairly recent in origin though those fingerings are old).
The fingerings are nice because they have no shifts.
Joe Pass used the same ones. Ron Eschete figured them out from listening to Joe Pass records"

Jimmy Bruno finger patterns below.

Danny1969

Being old I was never exposed to CAGE or even tab for that matter when I was learning. We had piano music and we worked out where to play it on guitar by writing the score into notes using FACE and EGBDF, then we knew where to play it on the neck because we had already worked out where all the notes on the neck were. 
I learnt Apache by the Shadows in A# minor  because that's what the score was in the piano book. Some of those transcriptions could be really lazy. 

What I have picked up over the years though is the knowledge of how every note relates in terms of intervals, not memory positions. To practice this just tune the strings away from normal pitch but still in relative pitch to each other, something like DADABD ... not for any chordal reason just because it makes the following hard. Now take a melody or solo you know really well and see if you can play it while mentally working out where the notes are now due to the different tuning of the strings. 

This forces you to think of notes and intervals, not patterns and it's a very useful exercise. 

As a teacher I don's use CAGE or any kind of tab. I want the student to understand what's going on using nothing but the math of music. Because i don't want to teach anything theory that's specific to guitar only. 

stratman3142

GuyBoden said:

Quotes from some Jazzers:

"As far as I'm aware, L.A-based session guitarist, Jack Marshall came up with the name 'CAGED' around 1950."

"it just wasn't called CAGED. Joe Pass was the first person I heard call it CAGED. (He called it that for teaching purposes; it wasn't called that when he learned it.)"

"Once upon a time someone asked Jimmy Bruno about "CAGED" fingerings and he went ballistic.
The fingerings are the same but that's not where Jimmy got them (-the "CAGED system" is fairly recent in origin though those fingerings are old).
The fingerings are nice because they have no shifts.
Joe Pass used the same ones. Ron Eschete figured them out from listening to Joe Pass records"

Jimmy Bruno finger patterns below.

That's interesting. So might that mean that they used the intervals of the major scale as a framework, and then adapted the intervals, as required, for other scales and chords.

In relation to CAGED I see that as:
Shapes 7(1) = E shape
Shape 2 = D shape
Shape 3 = C shape
Shape 5 = A shape
Shape 6 = G shape

mrkb

Thats a similar way to that Ive used CAGED to visualise how chord shapes, arpeggios and pentatonic boxes link up over the fretboard.

I tend to think of 6th string root note shapes are G and E, 5th string root note shapes are C and A, 4th string are D and top 4 strings of full E shape, 3rd string root note shapes are A and G, 2nd string root note shapes are D and C.

stratman3142

@kelpbeds your video is the best I've see on CAGED. Your comments around 11:00 especially resonate with me. I see CAGED as helping to make connections/associations and build upon information already known. I think it's what might be referred to as a 'meaningful learning' type approach, as opposed to learning by rote. 

@BillDL I started playing guitar in 1969 and came to CAGED is a similar way. 

I used to copy solos by the likes of Clapton, Page, Hendrix, Kossoff, Lesley West (and many others of that era). I started to notice certain recurring patterns. I could also add notes to the 'framework' patterns, to make other sounds. I think I first heard the term 'pentatonic' when Frank Zappa mentioned it in an interview. When I looked into it, I discovered that my framework patterns were called major and minor pentatonic scales.

I worked out that there were 5 major pentatonic shapes and 5 minor pentatonic shapes that could cover the whole fretboard. But really there were only 5 basic shapes, the major and minor just started on a different root note.

I could also see chord shapes within the major and minor pentatonic scales, so I could form a connection between chords and scales. I was applying a 5 shape approach, to visualise the fretboard, well before I associated it with the name 'CAGED'. I'd probably been playing well over 10 years before I started to use 'CAGED' as a label for naming things.

@mrkb : That's how I see the CAGED framework (pentatonic) shapes as well. The picture below shows how I visualise those diagrams over the whole neck for the C major and C minor pentatonics.

https://i.imgur.com/jN5P1gT.png

The 5 major pentatonic shapes give me a visualisation of the locations of the 1, 2, 3, 5 and 6 over the entire fretboard

The 5 minor pentatonic shapes give me a visualisation of the locations of the 1, b3, 4, 5 and b7 over the entire fretboard

I think the CAGED pentatonic framework shapes break the information down into manageable chunks. It would be a case of 'information overload' if I tried to visualise too many intervals at once. It's easy identify other intervals because those intervals are only ever a 1/2 step away from those in the framework shapes. So, for example, if I need to go to a b5 it's just a 1/2 step below a 5. 

Basic major chords are just a (1, 3, 5) subset of the major pentatonic shapes. Basic minor chords are just a (1, b3, 5) subset of the minor pentatonic shapes. I can create other chords by just selecting the intervals I need.

Scales and modes are just supersets of the pentatonics. For example, the Aeolian mode is just a minor pentatonic with the 2 and b6 added. And then I can get to the harmonic minor scale (ascending) by thinking of it as the Aeolian mode with a 7 instead of a b7. The CAGED framework patterns help to facilitate adaptable/reusable information and associations.

Pentatonics plus CAGED give me a framework/roadmap for the entire fretboard. Then I can visualise intervals, build chords and scales/modes as a subset, modification or extension (superset) of that basic framework.

I don't see 'CAGED' as a boxed-in constraint, but as a set of contiguous patterns. Things can flow seemlessly, or span, between the various patterns (e.g. 3nps).

One thing to mention, that I'm sure is true for all of us. When I'm actually playing, I'm not holding all this stuff in my head. This is mainly useful for practice, preparation, analysis, piecing info together etc. But I've generally (not always ) got an idea which CAGED framework pattern (or 2 contiguous patterns) I'm playing in, taking the root notes as my reference points.

I like the fact that CAGED is adaptable and flexible. People can approach CAGED from different directions and still end up with the same end results. Possible ways you could use it are:

1) Build up intervals from the bare bones root notes (octave patterns)

2) Build up from the arpeggio shapes

3) Start with the pentatonic shapes. Basic major and minor chords are seen as a subset. More complex chords and scales are seen as a modification/superset

4) Use the root notes to identifying major scale octave locations (1,2,3,4,5,6,7) then adapt those intervals to create chords and other scales.

kelpbeds

guitarjack66 said:

kelpbeds said:

I think one of the big issues with CAGED is that most people don't understand it in it's entirety. People understand bits of it (and then think they know the whole system) and then talk about it's shortcomings, not realising that it is actually a lot more comprehensive than they realise. CAGED encompasses different chordal voicing, a whole range of arpeggios, pentatonic scales, major and minor scales and modes. It's a way of putting different layers on the same concept rather than having different systems to deal with each concept. I decided to tackle all of this by producing a video which explains CAGED here.

I am going to have to dig into this a bit more,especially being able to play in certain sections of the fretboard. I still dont know all of the string inversions yet but my scale understanding is certainly improving and caged has helped this too.
You are very knowledgeable and talented my friend. You have now got a sub from me.

Cheers Guitarjack, your generous words are very much appreciated! And thanks for the sub!

kelpbeds

stratman3142 said:

@kelpbeds your video is the best I've see on CAGED. Your comments around 11:00 especially resonate with me. I see CAGED as helping to make connections/associations and build upon information already known. I think it's what might be referred to as a 'meaningful learning' type approach, as opposed to learning by rote. 

@BillDL I started playing guitar in 1969 and came to CAGED is a similar way. 

I used to copy solos by the likes of Clapton, Page, Hendrix, Kossoff, Lesley West (and many others of that era). I started to notice certain recurring patterns. I could also add notes to the 'framework' patterns, to make other sounds. I think I first heard the term 'pentatonic' when Frank Zappa mentioned it in an interview. When I looked into it, I discovered that my framework patterns were called major and minor pentatonic scales.

I worked out that there were 5 major pentatonic shapes and 5 minor pentatonic shapes that could cover the whole fretboard. But really there were only 5 basic shapes, the major and minor just started on a different root note.

I could also see chord shapes within the major and minor pentatonic scales, so I could form a connection between chords and scales. I was applying a 5 shape approach, to visualise the fretboard, well before I associated it with the name 'CAGED'. I'd probably been playing well over 10 years before I started to use 'CAGED' as a label for naming things.

@mrkb : That's how I see the CAGED framework (pentatonic) shapes as well. The picture below shows how I visualise those diagrams over the whole neck for the C major and C minor pentatonics.

https://i.imgur.com/jN5P1gT.png

The 5 major pentatonic shapes give me a visualisation of the locations of the 1, 2, 3, 5 and 6 over the entire fretboard

The 5 minor pentatonic shapes give me a visualisation of the locations of the 1, b3, 4, 5 and b7 over the entire fretboard

I think the CAGED pentatonic framework shapes break the information down into manageable chunks. It would be a case of 'information overload' if I tried to visualise too many intervals at once. It's easy identify other intervals because those intervals are only ever a 1/2 step away from those in the framework shapes. So, for example, if I need to go to a b5 it's just a 1/2 step below a 5. 

Basic major chords are just a (1, 3, 5) subset of the major pentatonic shapes. Basic minor chords are just a (1, b3, 5) subset of the minor pentatonic shapes. I can create other chords by just selecting the intervals I need.

Scales and modes are just supersets of the pentatonics. For example, the Aeolian mode is just a minor pentatonic with the 2 and b6 added. And then I can get to the harmonic minor scale (ascending) by thinking of it as the Aeolian mode with a 7 instead of a b7. The CAGED framework patterns help to facilitate adaptable/reusable information and associations.

Pentatonics plus CAGED give me a framework/roadmap for the entire fretboard. Then I can visualise intervals, build chords and scales/modes as a subset, modification or extension (superset) of that basic framework.

I don't see 'CAGED' as a boxed-in constraint, but as a set of contiguous patterns. Things can flow seemlessly, or span, between the various patterns (e.g. 3nps).

One thing to mention, that I'm sure is true for all of us. When I'm actually playing, I'm not holding all this stuff in my head. This is mainly useful for practice, preparation, analysis, piecing info together etc. But I've generally (not always ) got an idea which CAGED framework pattern (or 2 contiguous patterns) I'm playing in, taking the root notes as my reference points.

I like the fact that CAGED is adaptable and flexible. People can approach CAGED from different directions and still end up with the same end results. Possible ways you could use it are:

1) Build up intervals from the bare bones root notes (octave patterns)

2) Build up from the arpeggio shapes

3) Start with the pentatonic shapes. Basic major and minor chords are seen as a subset. More complex chords and scales are seen as a modification/superset

4) Use the root notes to identifying major scale octave locations (1,2,3,4,5,6,7) then adapt those intervals to create chords and other scales.

Oh man that's such a huge compliment, thank you so much.
 I spent years being misinformed about CAGED and not really getting it and then just researched it a ton until it all clicked. It's such a comprehensive system and is brilliant because of the layering idea. However, I would be lying if I said I only used CAGED, sure I use it but I also use 3NPS, intervallic stuff etc.....
You mention modes a bit later on in your post, I didn't really cover them in the video (at least not that I remember!) as I thought that might just overcomplicate things. But as you say they can be incorporated into CAGED by just thinking of the major or minor pentatonic, depending on whether it's a major or minor mode, and then adding the notes specific to that mode. 
And yes totally agree that CAGED is flexible and adaptable.
Cheers!

guitarjack66

stratman3142 said:

@kelpbeds your video is the best I've see on CAGED. Your comments around 11:00 especially resonate with me. I see CAGED as helping to make connections/associations and build upon information already known. I think it's what might be referred to as a 'meaningful learning' type approach, as opposed to learning by rote. 

@BillDL I started playing guitar in 1969 and came to CAGED is a similar way. 

I used to copy solos by the likes of Clapton, Page, Hendrix, Kossoff, Lesley West (and many others of that era). I started to notice certain recurring patterns. I could also add notes to the 'framework' patterns, to make other sounds. I think I first heard the term 'pentatonic' when Frank Zappa mentioned it in an interview. When I looked into it, I discovered that my framework patterns were called major and minor pentatonic scales.

I worked out that there were 5 major pentatonic shapes and 5 minor pentatonic shapes that could cover the whole fretboard. But really there were only 5 basic shapes, the major and minor just started on a different root note.

I could also see chord shapes within the major and minor pentatonic scales, so I could form a connection between chords and scales. I was applying a 5 shape approach, to visualise the fretboard, well before I associated it with the name 'CAGED'. I'd probably been playing well over 10 years before I started to use 'CAGED' as a label for naming things.

@mrkb : That's how I see the CAGED framework (pentatonic) shapes as well. The picture below shows how I visualise those diagrams over the whole neck for the C major and C minor pentatonics.

https://i.imgur.com/jN5P1gT.png

The 5 major pentatonic shapes give me a visualisation of the locations of the 1, 2, 3, 5 and 6 over the entire fretboard

The 5 minor pentatonic shapes give me a visualisation of the locations of the 1, b3, 4, 5 and b7 over the entire fretboard

I think the CAGED pentatonic framework shapes break the information down into manageable chunks. It would be a case of 'information overload' if I tried to visualise too many intervals at once. It's easy identify other intervals because those intervals are only ever a 1/2 step away from those in the framework shapes. So, for example, if I need to go to a b5 it's just a 1/2 step below a 5. 

Basic major chords are just a (1, 3, 5) subset of the major pentatonic shapes. Basic minor chords are just a (1, b3, 5) subset of the minor pentatonic shapes. I can create other chords by just selecting the intervals I need.

Scales and modes are just supersets of the pentatonics. For example, the Aeolian mode is just a minor pentatonic with the 2 and b6 added. And then I can get to the harmonic minor scale (ascending) by thinking of it as the Aeolian mode with a 7 instead of a b7. The CAGED framework patterns help to facilitate adaptable/reusable information and associations.

Pentatonics plus CAGED give me a framework/roadmap for the entire fretboard. Then I can visualise intervals, build chords and scales/modes as a subset, modification or extension (superset) of that basic framework.

I don't see 'CAGED' as a boxed-in constraint, but as a set of contiguous patterns. Things can flow seemlessly, or span, between the various patterns (e.g. 3nps).

One thing to mention, that I'm sure is true for all of us. When I'm actually playing, I'm not holding all this stuff in my head. This is mainly useful for practice, preparation, analysis, piecing info together etc. But I've generally (not always ) got an idea which CAGED framework pattern (or 2 contiguous patterns) I'm playing in, taking the root notes as my reference points.

I like the fact that CAGED is adaptable and flexible. People can approach CAGED from different directions and still end up with the same end results. Possible ways you could use it are:

1) Build up intervals from the bare bones root notes (octave patterns)

2) Build up from the arpeggio shapes

3) Start with the pentatonic shapes. Basic major and minor chords are seen as a subset. More complex chords and scales are seen as a modification/superset

4) Use the root notes to identifying major scale octave locations (1,2,3,4,5,6,7) then adapt those intervals to create chords and other scales.

Apologies for a bit of digression but how do/did you remember those pesky Pentatonics eventually? I have been playing about three years and only now am I starting to understand those pentatonics,but not too well. CAGED,in its basic form,has come to me much easier than pentatonic shapes even though I know they are sort of linked. I even do okay on fretboard navigation through mnemonics and the octave string skipping shapes,but those pentatonics are a problem for me.

stratman3142

@guitarjack66 what I described is just my way of thinking about navigating the fretboard, pentatonics and how it links to CAGED. It works for me, but I wouldn't want to suggest that it's the best way or that will work for everyone.

There are many guitar players (better musicians than me) that don't use CAGED. Take @viz and @Danny1969 for example. I expect their natural musical talent and ears are much better than mine. I had a certain amount of natural ability for maths and science, but virtually zero natural ability for music except for lots of determination to want to play rock guitar. So I looked for ways of classifying things, identifying patterns and making associations between things.

Regarding memorisation of pentatonic shapes, I started by using Forms 1, 2 and 4 of the diagrams in @mrkb 's earlier post. I think most of the solos I learned in the early days (from Clapton, Hendrix, Kossoff, Lesley West etc) would fit around those forms. They might add the odd extra note such as the b3 to the major or the b5 to the minor, but those were the basic framework shapes. There's a lot of mileage in just those three basic framework shapes/forms. 

I originally thought of the minor pentatonics as being created by shifting the major pentatonics up by three frets. For some reason I started by thinking in relation to major pentatonics first, but I think a lot of players think minor pentatonic first, in which case you could create a major sound by shifting the minor pentatonic patterns three frets lower.

Although it helps in getting the patterns under your fingers, the problem with the pattern shifting approach for me is that it's too disconnnected from knowing which intervals are being played. So I moved to thinking of the shapes (or forms) relative to their root notes. It was still three forms, but starting on different root notes. I'm not just thinking in terms of patterns and shapes, but also as intervals relative to the root notes.

So, for the major pentatonic patterns, I mainly think in terms of the G maj shape, E maj shape and  C maj shape. Which are Forms 1, 2 and 4 of the diagrams in @mrkb 's post

For the minor pentatonic patterns, I mainly think in terms of the Em shape, Dm shape and Am shape. Which are again Forms 1, 2 and 4 of the diagrams in @mrkb 's post.

I started to use Forms 3 and 5 to fill in the gaps between the other forms. They're now part of my thinking to create a framework covering the whole fretboard.

For my reference points, I focus on the relative positions of the root notes. If the relative positions of the root notes look like they do in an open C chord then I call that a C shape. If the relative positions of the root notes look like they do in an open A chord then I call that an A shape etc.  This applies whether it's major or minor, which gets around the problems I used to have in knowing how to apply CAGED to minor chords and scales.

Rocker

Good Lord!  I read some of the replies and my brain is frazzled. This subject is overthinking on a grand scale. It is important to remember that we are playing music not studying rocket science. Music that should be fun to play. Not a subject that requires detailed in-depth study. I will look at the video later. And hope my brain can cope.......

mrkb

Rocker said:

Good Lord!  I read some of the replies and my brain is frazzled. This subject is overthinking on a grand scale. It is important to remember that we are playing music not studying rocket science. Music that should be fun to play. Not a subject that requires detailed in-depth study. I will look at the video later. And hope my brain can cope.......

The good thing about guitar is you can use just one finger, or progress onto more advanced techniques! Use whatever floats your boat.

Keefy

Rocker said:

Good Lord!  I read some of the replies and my brain is frazzled. This subject is overthinking on a grand scale. It is important to remember that we are playing music not studying rocket science. Music that should be fun to play. Not a subject that requires detailed in-depth study. I will look at the video later. And hope my brain can cope.......

The two are not mutually exclusive - I for one hugely enjoy both.

Lewy

Rocker said:

Good Lord!  I read some of the replies and my brain is frazzled. This subject is overthinking on a grand scale. It is important to remember that we are playing music not studying rocket science. Music that should be fun to play. Not a subject that requires detailed in-depth study. I will look at the video later. And hope my brain can cope.......

If you want to limit yourself to playing the kind of music that requires no detailed in-depth study then good for you, but that doesn't mean that people who don't want such limitation are guilty of overthinking on any scale. 

CaseOfAce

Rocker said:

Good Lord!  I read some of the replies and my brain is frazzled. This subject is overthinking on a grand scale. It is important to remember that we are playing music not studying rocket science. Music that should be fun to play. Not a subject that requires detailed in-depth study. I will look at the video later. And hope my brain can cope.......

I think you've got a valid point in there Rocker - I wouldn't go so far as to state it was over-thinking..but in some ways I agree. If you get too bogged down in the "how" / theory of why something works it can lead to adhering to strict rules of using the only the "correct" chords in a key when writing songs or using the "correct" scales when improvising solos - and you end up missing out on those happy accidents that leads to interesting music (Keith Richards says when he was jamming at home he'd make a "mistake" and come up with a song as a result...).

Cobain made some wonderful stuff using a collection of ham-fisted power chords (that intro to Lithium with that vocal line over the top !) - but by the same token Mike Stern doesn't seem to have been hamstrung by the rules of theory as regards his creativity - and in his case knowing the how and why of soloing over diminished chords is probably a useful skill to have.

Dunno.. I'm still trying to figure all this out myself.