Ah so you want a simple kernel for your machine that's too noisy to be your media player. Almost os can do that, but pcbsd is overkill for your machine. if all you want to set up is a running sound database, but beileve your machine is moderate in its power I prefer you use dynebolic (
http://dynebolic.org/). It won't solve your machine "noise" problem because that's a BIOS thing (assuming we are talking about the (primary) secondary storage device (hard drive) sound or the fan). There are ways to get around that after a kernel boots (like accessing BIOS option after the BIOS, or editing the BIOS by the OS)
if you want to install something something even more simple (an almost dying machine of old age) pupylinux, dsml, mfsBSD, netbsd, etc. (something that uses little processing power). Then install the minimal apps, like mplayer, a script to run with mplayer, and forget about a database (unless u intend to share with other comps, I still suggest no database, just an NFS partition, let users log in the NFS, and download any files from there, even play lists). I believe there's even smaller better music players that support play lists than mplayer, but right now i forgot most of them. In freebsd there are lots.
but since i don't know your plan, I assumed very much. For all I know, you can install freebsd, get one of those awesome small music player that support playlists, make your files be under a NFS partition (not the entire OS), remove almost all other apps from freebsd base install, compile a new small kernel for the lolz, add speakers and its "driver" (i.e. if_pcm_load="YES"), install a simple wm like dwm or fluxbox, and have a blast playing with all the fun freebsd has to offer (like ports).
reply here, or email/pm me about your plan, we can probably help. just plan it out.