I've read somewhere that tetratonic scales have been extensively played in jazz from Lester Young to Mulgrew Miller. I understand they are derived from the melodic minor scale. Could anyone explain to me how they are built and which chords they can be played over?
UPDATE: I think I have answered my own question:
The tetratonic scales should contain the tonic, the minor third, the fifth and the sixth of any melodic minor scale.
For example, the tetratonic scale of C would be C-Eb-G-A.
Now one needs to figure out the only major scale which has these notes; in this instance, it is Bb MAJ.
When you play the C melodic minor tetratonic scale over the Bbmajor scale, you highlight the 9th, the 4th, the 6th and the 7th of that scale.
It's interesting because you leave the tonic and the fifth aside.
I took a step further with a very simple progression (eddie harris's "listen here") Bb7 and Eb7. Now I decided that the key is Ab; in Roman numerals that would make the song a II7 - V7 The tetratonic scale for Ab is Bb-Db-F-G and it works nicely on Bb7 because Db is the b5 of the G blues scale and also over Eb7 because Db is the b7 of that chord. So the tetratonic scale can work on the whole cadence and is very useful to add approach notes. You can also spot the third of the chord easily if you want it.