Sample features:

1. input a set of notes, output fitting scales {haskell-prototyping.hs: improScale}
2. input a scale, output its chords {haskell-prototyping.hs: scalechords}
3. recognize known chords and scales {haskell-prototyping.hs: ictRecognizer}
4. print all seventh chords within a given scale
5. input a melody, output a harmonization
6. input keys X, Y and an n, output n keys on a tonnetz/circle-of-fifths/... geodesic of X & Y
7. input a chord progression, output its negative (in the sense of Ernst Levy)
8. run fretboard quizes {haskell-prototyping.hs: fretboardQuizOneStandard, fretboardQuizTwoStandard}

You may compile the source text by running "ghc haskell-prototyping.hs" on a terminal and then open the program by entering "./haskell-prototyping".

Contents of file haskell-prototyping.hs:

0. Preamble and stolen stuff
1. An enumeration type for notes
   1.1. Application: Impro suggester
   1.2. Application: Scale chords
   1.3. Application: Interval-chord-scale recognizer
   1.4. Application: The seventh chords of a scale
   1.5. Application: A literate suggester
2. An inductive type for chord constructions
3. About rhythm
4. Tymoczko chord change spaces
   4.1. T-Closeness
5. Concerning the guitar
   5.1. Application: Fretboard quizes