VGMSlap (VGM Silly Little Adlib Player) is an open-source, MS-DOS based player for Yamaha OPL1/2/3 Video Game Music (VGM) files. It features a visually pleasing display of each synthesizer channel's parameters, GD3 tags, and simple playlist support.
See the program readme (VGMSLAP.TXT) for additional info.
VGMSlap is written with Open Watcom C 2.0 in mind. Assuming you have your Watcom environment variables and PATH set correctly, just run wmake from the source directory to create vgmslap.exe.
The VGMSlap software and code itself is licensed under the MIT License (see LICENSE).
This VGMSlap source distribution also incorporates a prebuilt zlib 1.2.11, the last version I could get to successfully compile for DOS on Watcom, which is licensed under the zlib license (see zlib/LICENSE).