slide: Processing MIDI file

The actual processing is depicted in slide midi-processing. The input is a MIDI file. As indicated in the top line, the MIDI file itself may be generated from a Lilypond file. Lilypond is a \LaTeX-like formatting language for musical scores that also supports the generation of MIDI  [Lily]. As indicated on the bottom line, processing a MIDI file results in a collection of features as well as in a MIDI file and Lilypond file. The (result) MIDI file contains an extract of the original (input) MIDI file and the Lilypond file contains a score for this extract, that may be presented to the (end) user as the result of a query. This setup allows us to verify whether our extract or abstraction of the origanal musical structure is effective, simply by comparing the input (MIDI or Lilypond) musical structure with the output (MIDI or Lilypond) extract.