Hi, I don’t know about the specifics of audio applications. However, in general, it should hopefully be relatively simple to provide distro configurations tailored to specific needs–like the “media production” distro you have in mind, things like TAILS, etc.
Ideally, it would boil down to preparing a custom ‘operating-system’ declaration–with all the services and packages of interest ready to use–that users would inherit from to further customize things. At this point the Guix System Distribution is still very much for hackers rather than newcomers, but I would love to see projects like this one grow. Thanks for your interest. Ludo’.