- Find out the histogram of pitch class usage over the 12-bar blues progression. Something like an "average" blues song.
- Get some blues songs (eg. 1000) with 12-bar progression.
- Segment out the 12-bar blocks.
- Compute the pitch-class profiles (from the harmonic content).
- Compute the key for each block.
- Normalize the PC profiles using the key (and also the volume) of the block.
- Aggregate the PC-profile blocks (average them).
- Additionally produce an "average blues" synthesized music.