Absolutely Understand Guitar. Cool YouTube channel if you wanna learn music theory.

equalsql

Recommended to me.
It's a complete course for free.

Neilybob

I could do with some of that. Thank you very much 

munckee

If I learned theory I would have no excuse tor being rubbish. 

viz

I dunno, I understand how and why music works and I’m rubbish at the guitar; I just say they’re different things

mrkb

munckee said:

If I learned theory I would have no excuse tor being rubbish. 

But at least you’d understand why it’s sounded crap!

BillDL

If I was going to make a superficial judgement on the potential content of the series of videos (Playlist Link) I believe I might have been put off a bit by the QVC style introduction that sounded very mechanical, however I have skimmed through a few of the videos in order and the content is well sequenced and presented.  I'm not a teacher, but I know enough theory to teach to a reasonably high level, and I think there are a couple of fundamentals that I would probably have introduced in a different order for a course.  He will have his reasons for ordering them that way though, and I think these videos would enable people with little or no understanding of theory to come out the other end fully understanding how music works, and without making them feel like it was drudgery in the process.

ArchtopDave

Horses for courses. I found him tedious, and he spent too much time talking about irrelevancies in terms of developing an understanding of Music Theory. I have learnt a fair amount of Music Theory during past guitar lessons, and will admit to liking Music Theory.

 On top of this, I paid for Lifetime Access to Justin Sandercoe's Practical Music Theory Course quite awhile ago. I don't think that you can do that any more, and I'm pretty certain that you now pay by subscription. From my point of view, it's a much better organised course, but I know full well, that in music, different styles of teaching suit different people.