Soloing over a secondary diminished 7th chord

Axe_meister

Just going through the Beato Book and currently going through secondary dominants. Now for a standard secondary dominant.
Say C to Dm I could go C A7 Dm I could branch out to A mixolydian before coming back to C major but what about if I go C C#dim7 Dm, Any particular scale choice or would be best course of action be to take the chord tones of C#dim7?

Brad

C#dim7 acts as an A7 anyway so you could use a C#dim7 or A7 arpeggio or A half/whole diminished (or C# whole/half dim - same thing) or A Altered.  

That’s a lot of choice already, so pick one and really spend time with it. The beauty of it being that you can use these scales even if that secondary dominant isn’t there. 

ae1734

You can also try A Phrygian dominant (a mode of D harmonic minor) to resolve to the D minor. This has the C# diminished in it. 

tabano

over C#dim7 moving to a Dm in the key of C major you could  play D harmonic major, C# superlocrian, F harmonic major, Bb melodic minor, also E superlocrian and all of the above replays suggested to name a few..
there are a bunch of options depending on the context although to my ears, they work best when resolving to a chord tone over Dm7 when you land there..

jazzlemming

Yes, there are technically a few choices here, but really I think it's important to understand that there is a hierarchy of sorts. If you choose the scale that not only matches the chord tones but also matches the largest number of notes of the tonal centre you're going for, that's generally going to be the strongest choice. So here, like @ae1734 suggests, that's going to be D harmonic minor (or A Phrygian dominant) because you're going to D minor.

Next choice would be A altered (Bb melodic minor or A super locrian to 1980s rock guitar students!) which works really well but imo it requires more work and understanding to start employing that sound (eg. there's a (relative to the tonic Dm) b7 and M7 and a b9 to get your head and ears around!).

Then A half/whole works and there's a whole world of diminished to explore, although as well as the difficulties of A altered you've also got an F# which makes it slightly further away from the D minor (with its minor 3rd of F natural).

Beyond that I think we're getting into some more esoteric choices which are best explored once the above have been mastered.

And of course, as @Brad mentioned, the arpeggios always sound strong, so C# dim (and therefore E dim, G dim, Bb dim) will make your lines sound well-defined and focused. I would start here and then move on to integrating those extra notes from D harmonic minor.

viz

The other good one, which is v similar to A phryg dom, is A mixo b6, which is the 5th mode of D melodic (rather than harmonic) minor. Same as A phryg dom except the 2nd note is a B instead of a Bb. Same notes as Tabano’s C# superlocrian. 

Roland

viz said:

.... Same notes as .... 

It’s the notes which are important, not the name of the scale which includes them.

viz

Roland said:

viz said:

.... Same notes as .... 

It’s the notes which are important, not the name of the scale which includes them.

What I meant was “Oh, and I’ve just spotted that Tabano already covered this set of notes earlier”. 

But seeing as you raise the point, I don’t actually agree with it. It is important in the same way that it’s important to distinguish between C major scale and A minor scale. They’re not different names for the same thing, even though they contain the same notes, so that’s important, at least for me it is.  

HAL9000

I’m not as up on my theory as some of you but if that sequence turned up in a song I feel I’d be treating the diminished chord as either an A7 or, more likely, a C7. I’d essentially stick to a C major scale but would probably target E, G, and Bb (and avoid C).