Visualising MIDI files with Python

Plug — I’ve since done even more work with MIDI and created a MIDI to LSDJ app in Python

I’m really into music, If you spend 5 minutes talking to me you’ll probably realise that I care a little too much about how particular songs, albums and bands make me feel when I listen to them and why other bands just don’t cut the audio mustard.

I have a growing collection of notation files on my computer for my favourite songs, these are often in Guitar Pro (me being a guitar player) or in MIDI. The latter comes in very handy when I want to record myself playing the guitar parts as I can just import the drum track and the tempo and time signature changes are brought in with it.

I found this awesome Python library for parsing MIDI files and decided to hook it up to Matplotlib to see if I could visualise the notes in the file to make a nifty little representation of the song.

I’d used Matplotlib before at a hack day where we were parsing DICOM files and using Matplotlib to plot the x, y and z values we were able to build a 3D representation of the data in the file relatively easy.

Converting MIDI to a line

The python-midi library gives you a really helpful method called read_midifile which handles the loading and parsing of the MIDI file.

The result of the read_midifile method is a list of MIDI tracks which each contain a list of MIDI events such as:

• Setting the tempo —…