A plugin I made which plays atmospheric HL2 music for players every 10-15 minutes. This is adjustable, however. I only chose songs that were not upbeat or had drums, so for most players this should just fade into the background for them, hence the name Background Music. A similar idea to this has been done with IronWall HL2RP, but was dependent on players setting zones for music, which I think is totally unnecessary.
Install and enjoy, any errors should be put in the comments or reported to me on my steam page.
I will make a forum thread about my plugins later today, maybe! :D
Your plugin seems to be broken, I have added you on steam to sort things out!