mm.Recorder allows you to record MIDI from a MIDI instrument,
and converts it to a NoteSequence. Note that these demos won't work
unless you actually have a MIDI instrument connected to your computer.
Once you create an mm.Recorder, it will connect to any MIDI inputs
visible. You can use start() and stop() to record
a NoteSequence:
You can also enable the mm.Recorder to record in streaming mode.
In this case, the recorder will emit a new NoteSequence every time a new
note is recorded, rather than just the entire sequence at the end of the recording: