As we all know, looping music is as simple as adding two cues “[” & “]” in Anvil Studio. However, Anvil Studio only runs on Windows, and Mac OS Catalina has compatibility problems with Mono, Wine, Crossover and so on. I don’t think it is worth installing virtual machine just for such a small thing.
If the song only has 1 track, then just edit the .s file directly. It is quicker than opening another software.
Hack mid2agb to loop music automatically. Here is it.
Use an alternative to Anvil Studio to add “[” & “]”. It is difficult to find a “new cue” button in other midi editors, but in fact, it needn’t to be a cue. By reading source code, I find that any special event like Marker/Text/Cuepoint works, as long as its name is “[” or “]”. Then it is simple, because most DAWs support markers. For example: