One of the most interesting traits in musical compositions is malleability.
It’s anathema, perhaps, to Performance Practice-minded interpreters, but music is malleable–it can be reinterpreted to different sensibilities. But realize this: malleability is not a constant. Some songs are more malleable than others.
For example, consider a song like “Autumn Leaves.” This song is exceedingly malleable. It can be compellingly interpreted as a ballad, a slow swing, an up swing, a bossa nova, an odd-meter tune, and more. If you survey 25 versions of the song on Spotify, you’ll hear 25 different interpretations.
Other jazz songs are less malleable: either because they are associated with a particular interpretation – say, Monk’s “Rhythm-A- Ning” – or because they are just less welcoming of change. Consider the Billy Strayhorn classic “Lush Life.” If you survey 25 versions of that, you’ll hear a lot of similarity.
Part of what I look for as an arranger is malleability, because unless a song is somewhat malleable, it’s difficult for me to add my own voice to the composer’s. We can’t create the dialogue that is the hallmark of the best arrangements.
How do you assess malleability? By listening, by experimentation, and eventually by learned intuition.