Supplemental
Python libraries built for the apps on this site, and extended for other developers to use: definitions of the MIDI specification, and of the MIDI messages popular instruments answer to.
MIDI Specification Definitions
Comprehensive MIDI 1.0 and 2.0 constant definitions for Python.
MIDI Instrument Definitions
These pages set out the MIDI messages a number of popular instruments answer to, each read from its maker's own documents.