Keep it simple until you are comfortable with the changes.
When you run into the repeated C7,Bb7,C7,Bb7, such as in Killer Joe, just play around on C7. In other words, improvise lines based on the F major scale, but keep C7 in your head.
The harmonic context of that sequence is C7. That notion breaks the rules, but it works. Here's how a Bb7 is really a C7.
The Bb7 spelling adds a 9th (D) to the C7, augments the 5 (Ab), suspends 4 (F), and puts 7 (Bflat) on the bottom. But you can let the piano and bass worry about all that. Just riff on C7 and it will sound just fine. Even a little bit outside.
If it's easier, think of the Bb7 as a G7alt/Bb, but I don't think that's easier.
When you run into the repeated C7,Bb7,C7,Bb7, such as in Killer Joe, just play around on C7. In other words, improvise lines based on the F major scale, but keep C7 in your head.
The harmonic context of that sequence is C7. That notion breaks the rules, but it works. Here's how a Bb7 is really a C7.
The Bb7 spelling adds a 9th (D) to the C7, augments the 5 (Ab), suspends 4 (F), and puts 7 (Bflat) on the bottom. But you can let the piano and bass worry about all that. Just riff on C7 and it will sound just fine. Even a little bit outside.
If it's easier, think of the Bb7 as a G7alt/Bb, but I don't think that's easier.
