SatouSynth is a VGM emulation and playback library written entirely in Common Lisp. This video shows it emulating the Yamaha YM2610 chip by playing the Stage 1 theme from the game Metal Slug on the NeoGeo AES, written by Takushi Hiyamuta (HIYA!) and JIM. It's being played in Emacs using Slime and a very small example player.

SatouSynth is currently in development and is not quite ready for its v0.1.0 release. The source code for it can be found here: https://nanako.mooo.com/fossil/satousynth/