One of the things that overwhelmed me when I first tried soloing over changes in jazz was how fast the chord changes often pass. How could I change scales that quickly and express anything? An instructor I worked with years ago taught me a way to simplify a series of changes by looking at what key the chords are implying. Here's how you do it.
First, let's look at the A section (the head) of Line For Lyons by Gerry Mulligan:
| G6 G7(b9) | Cm7 F7 | Bm7 E7 | Am7 D7 | | GΔ7 E7 | Am7 D7 | G6 E7 | Am7 D7 |
If you aren't familiar with jazz notation, Δ means "major".
We can reduce some of these chords down to their base forms:
| G | Cm F | Bm E | Am D | | G E | Am D | G E | Am D |
Knowing that ii-V is the most common chordal movement in jazz, that's one of the first things we can look for and identify what keys those ii-V movements occur in and then use that key as the scale:
| - - - - G - - - - -| - - - Bb - - - -| - - - A - - - - | - - - G - - - -| ii V ii V ii V | G | Cm F | Bm E | Am D | | - - - - - - - - - - - - - - - - - - G - - - - - - - - - - - - - - - - - | I VI ii V I VI ii V | G E | Am D | G E | Am D |
Normally, in the key of GΔ, the vi chord is minor, but there are a various number of ways to include a major VI, such as modulation via common tones (other than the 3rd) or it could be the VI of the G minor scale. At any rate, don't lose any sleep over this anomaly, just throw in G# passing tone when you hit this chord and focus on E and B.
We've reduced 8 bars of 2-beat changes to 8 bars of GΔ with 2 measures of descending major scales (the Bb and A section). Now you only have to worry about those two bars and then just play over GΔ for the rest.
There are, of course, many other ways to reduce this. This is just one way. If you can think of another way to reduce this sample, I'd love to hear your suggestions. Use your ear and throw in more chord-specific tones in your soloing as you improve.