So you’ve played a million 3 chord songs, and along comes a tune that has a bunch of altered 5 (altered dominant 7) chords, and you’ll be taking the solo.
How would you approach a C7#5 chord? One scale to use is a whole tone scale; all whole steps starting on C.
Its a 6 note scale C, D, E, F#, G# A#. When improvising consider how the 5th resolves. The G# often resolves to an A (often the 3rd of an F maj chord). Sometimes the V7#5 lasts a long time, or resolves to another dominant chord with an altered 5th . Extending time on this scale provides an “airy” quality. This scale could also be used if the chord were a C7b5. Here the Gb often resolves to an F (possibly the root of an F minor chord). In either case, try shaping your line so that the half step resolution happens right as the chord changes. Generally, if the 5th of a chord is altered, you can play both the b5 and the #5 in your scale, but avoid the perfect 5th unless you use it as a quick chromatic passing tone.
What if the chord has an altered 9th? C7b9 would most often call for a scale like C, Db, (D#), E, F, G, A, Bb. Note that we can use the same scale for a C7#9 chord. (I’m using 9 the same as 2 in this scenario). Again, if we alter the 9, we can use both the #9 and the b9 in the scale, but we tend to avoid the natural 9, just as we did with the 5 in the previous paragraph. Also, remember to look at the resolution in the following chord to help shape your solo line.
What if the chord has an altered 5th, and an altered 9th? C7b5b9 for example. You might try a diminished whole tone scale: C, Db, D#, E, Gb, G#, Bb.
This scale usually works well if both 5th and 9th are altered in either direction. These chord shapes are very commonly used as a cadence in a minor progression. (ex: C7#5b9 to Fmin7).
You should notice that I have used non-absolute statements in this article. There are definitely other choices for scales over these chords. It’s my opinion that the right player can make any note sound good with any chord if he chooses the right line for the context. However, players should know these scales as common musical flavors, and choose to use them or not after they are under the fingers.
All of this looks pretty academic on the surface. It’s probably not stuff you hear on most 3 chord tunes, but it will come up. You don’t have to know any of this if your stuff always sounds good. I just throw the musical math out there for those who need a boost getting through these chords.
Get to know how these altered dominants sound, and how they resolve. Then create melodies as you solo, using parts of scales or arpeggios on the suggestions above. The altered dominants will quickly be part of your musical vocabulary.
This article is written by James Albright, a top jazz musician and producer in Kansas City. Read more about James at JamesAlbright.com