Hi there,
the representation of chord degrees and scale degrees is helpful and works pretty well.
However, limiting the scale degrees to just the 12 “straight” pitches and leaving out the blue notes (mainly the “blue third” (note between b3 and 3) and the “blue seventh” (note between b7 and 7) makes it impossible to create a very large part of “western” music, like nearly all Blues and many bluesy Rock and bluesy Funk melodies.
Implementation could be relatively easy (unlike the gliding from note to note discussed elsewhere):
As HookTheory works with samples, you just need to create a few more samples: The 12 in-between notes. They could be used as blue thirds and blue sevenths.
As blue notes are not simple pitches but “pitches in motion” (in the key of c starting at or slightly below eb and moving higher at the end of the note to around the mid-point between eb and e) and this upward motion is dependent on the note length I spontaneously can come up with to solutions (depending on how HookTheory handles note lengths):
To fit different tempos the new blue notes could be time-stretched or to get different lengths the beginning of the notes (the part that is not bent up) could be cut for shorter notes (instead of the end as it’s probably done with the other pitches).
I you want to discuss this further and need a well-known (at least in Germany Blues expert that is also experienced with sampling and music software beta testing: I am happy to help!
Andi