I use mpv commandline tool to play music in a loop, seamlessly. You open an audio file, press “l” (lowercase L) at the starting point, then use arrow keys to go

I use mpv commandline tool to play music in a loop, seamlessly. You open an audio file, press “l” (lowercase L) at the starting point, then use arrow keys to go to the and point and press “l” again. That’s it. The only problem is to press the keys precisely at a music bar boundary, but with enough practice you can get pretty close so the seam is barely noticeable or not noticeable at all.