music21 version

5.7.2

Problem summary
noob request
I have helped to write a fretboard exercise which switches scale periodically. MelodicMinorScale respects the tradition of altering 2 notes depending whether ascending or descending, but jazz musicians generally regard melodic minor as just the "ascending" mode (ie major 6th major 7th) regardless of direction. If there is a scale within Music21 that gives me this result, I cannot find it. Would I need to define my own scale?