Your question is a good one, but I think you can go about it in a slightly different way and end up with much more meaningful results.
If we acontextually (that is, away from the music itself) try to compile a list of various musical traits, it will never be complete and it will never be specific enough. So instead of trying to list musical traits and then trying to map them onto particular performers, I recommend starting with the performers themselves.
Start small, with a single album from a single performer. Learn it (from an aural standpoint) inside and out. Once you've done this, try to describe general trends in what you hear.
Then, find another album from the same performer from around the same time period, and do the same thing. Now ask yourself: what traits are consistent between albums? (That is, "what traits can you start to say are consistent within this performer?") What traits are different between albums?
Next, find an album from the same performer that was made 30 years after the previous two. What changes can you determine within this single performer? (Almost every great artist changes throughout their career.)
Then go on to other albums from other artists, slowly building up a repertoire of general trends, and soon you'll be able to compare and contrast various styles, composers, performers, etc.
This approach will certainly take more time, but there is one major advantage compared to us listing off some general ideas and you trying to match them with performers: Going with the latter approach, I worry you're more likely to miss major innovations that some performers bring to the table, and your understanding of these styles will correspondingly be a little limited. But when you start with the music itself, in my opinion you'll much more easily spot innovations when they do appear.
To give a stupid example: I want to compare and contrast forms of transportation. I ask for traits to look for, and someone says "number of wheels." By this strategy, I might not recognize what an innovation the first airplanes were compared to the tricycle, or what an innovation the Model T was compared to a horse-pulled wagon. But if I were to start with the modes of transportation themselves, these innovations are impossible to miss.
It's a silly example, but my worry is that the "list of traits" potentially creates some tunnel vision that will blind you to some of the really important features.
This way takes more time, but I think the outcome is far better.
