I previously recommended Xubuntu 22.04 as a good distro for playing music, at least until Pipewire gets fixed and I can go back to using MX-Linux as my Swiss-army-knife installation. But after using Xubuntu 22.04 for a while, I've decided to drop it because of all the deliberate nuisances built into it, such as pop-ups which are the only indication of a supposed system problem, whose real purpose is to freak out newbies. (It's like a diagnosis of a disease with no symptoms.) It also performs frequent "unattended upgrades" even on my air-gap PC which obviously could not have downloaded any upgrades. They bog down my CPU, and when I try to shut down the PC, they prevent it from happening, although I press the start button until it shuts down. If those were the only ones, I'd put up with them, but there are others.
So, I've been using Ubuntu Mate 20.04 for playing music. It too has the two aforementioned nuisances, and perhaps others, but so far within tolerable limits. (Windows also has such nuisances, or at least it did when I stopped using it over a decade ago, when an update killed my laptop.) Ubuntu Mate was my favorite before finding MX-Linux (I also like Kubuntu), but now that I've stumbled onto using µSD cards combined with fast µSD-to-USB adapters for encrypted full installations, it's easier to use UM as a secure installation for an air-gap PC because of the relative speed of creating µSD-card installations, and their energy efficiency, vs. these same aspects of USB3 installations. (Putting installations on removable drives makes it easier to secure them when not in use, although if they're nonpersistent live installations, there's no need to secure them since they contain no sensitive data when they're shut down, and they can be easily replaced if stolen.)
If UM live installations booted quickly, like MX-Linux live installations, I'd use Cubic to create custom UM ISOs, and use them to create nonpersistent live installations. But by editing the installation to eliminate the need for user-input during the booting process [1], and by using a faster PC, live custom installations of UM would be a viable alternative to MX-Linux live installations for secure PCs.
Notes
[1] With nonpersistent live installations, which don't store any data upon shutdown except what's baked into the ISO (which presumably wouldn't be sensitive), there is no need to log-in when starting the system, although you would want a password so that you could perform superuser-functions, and lock the system during a session, and resume.
