Green Dolphin Street is one of my favorite types of standards to improvise on. It mixes modal progressions with Bebop. Take a look at the chart below. The "A" sections will be played using a modal technique and "B" and "B1" will be played in a Bebop style.
Let's start with the "A" sections. For this modal section, we will use a technique called "Common Tone Approach." This is a great tune to demonstrate this technique because we have a "C" pedal tone through most of the "A" section. As the name suggests, we will use a common tone to help us generate the modes we need to improvise. In other words, all of our modes will use the "C" note as their roots. Let's begin.
So, how did I find these 4 scales? Let's take a look. C major scale for the C6/9 should be straight forward. We're in the key of C and our chord is a I chord so we play C major scale.
Next we have an Eb/C. If we were to write out all the notes on a staff using C as the bass note we would end up with a Cm7 chord. Therefor, for Cm7, we can use a C Aeolian mode.
D/C gives us a chord very close to Cmaj7(#11). We have the root, 9th, #11 and 13th. We have neither the 3rd or 7th but if you play a voicing for Cmaj7(#11) and then play your D/C chord, you will hear the similarities.
The last chord, Db/C, should first be visualized as a Dbmaj7. We have a Db triad with an added C note. The C note is the major 7th of Dbmaj7. Now there is a rule that states all maj7 type chords which are not the I chord of the key should use the Lydian scale. In other words, the only place you should play the Ionian mode (Major Scale), is for the tonic chord of the key. All other maj7 type chords will use the Lydian mode. Now there is still one more step. We want all of our modes to have "C" as their root. If we agree that all 7 modes from any scale all share the same notes but have different roots then it's fair to say we can start our Lydian mode on another note and we will not have changed any notes in the scale. What if we start the Db Lydian mode on the 7th scale degree or the C note but we don't change any of the notes, we only start on "C" instead of "Db." A Db Lydian mode fron "C" to "C" becomes a C Phrigian mode.
Let's take a look at a solo. For this solo, I will use the modes above and try to tie them together musically using motivic ideas. For both B sections, I played in a Bebop style. Playing in this style is discussed in my book and will also be covered in another Improv lesson soon to come. You can find the melody to this song in numerous fake books and on the web.
If you liked this lesson, why not download one of the "Jazz Guitar Elements" free samples. Available for iBooks or in PDF format with mp3 audio tracks. There's enough information to get you started.