The list book tags any phrase in a phrase category ending in 'b' as "specific." So for example, 'Db', 'Bb', etc. I think that indicates it was based on an existing song. And anything ending in 'a' is more generic.
Haven't verified this thoroughly, but that's my understanding, which would mean styles that use phrases in the "specific" categories would be the ones based on real songs.
If I'm correct in my understanding, that would narrow down which styles to scan when trying to match them to songs on which they're based.
