feature request: allow playing of MIDI files (SMF)

[andlabs]

I wanted to play a MIDI file through my USB-MIDI interface on a Mac running macOS 10.12. It turns out this is not trivial; unless you use a DAW the only relevant results are for installing QuickTime 7 to play a MIDI with a built-in MIDI synth (like GM.DLS on Windows) instead, or they point to this tool for sending raw MIDI commands to a device. Since this appears to be the big MIDI-on-the-command-line tool going forward, making it a one-stop place to send SMF-format MIDI data to a device would also be useful.

(I did try using VMware to play the MIDI file from a guest OS, in this case Linux with aplaymidi; for some reason, the device never registered it was getting MIDI data from the OS... I probably did something wrong there. I eventually had to use Python's mido library, which includes a sample program to play SMF files, but I needed to patch the code a fair bit to get it to even run, due to various Python-y bugs. I might report those upstream too.)