Aha!
I'm running pc-compatible Deskmate 3.05 on my Tandy 1000 and I've always been confused about the lack of a 3-voice chip sound player when the #TVDog Deskmate archive at oldskool.org has a bunch of music files...
According to http://nerdlypleasures.blogspot.com/2024/07/tandy-deskmate-tandys-ace-in-hole.html
This is because generic DM 3 doesn't include the sound player, I need to grab it from DM 3.02 for the TL/SL!