There's nothing wrong with instrumentals, I mostly recommend those. Done and done.
Also, remember that I can make the music start off immediately when you arrive on the forum's main page, yet every-time you change page, the song stops and when returning on the main page, if will restart and reload again. Your call.
The actual method requires us to click the link, but the music don't download immediately without our consent to listen to it. It pops-up into another window and allow us to visit all pages of the forum while listening to it. Only inconvenient, other than having a full window for the song, is to click on it ourselves.
The other method (Auto-read) is saving us from clicking the link immediately, yet there's two main inconvenient. First of, people who don't wish to listen to it would have to stop it manually every time they open the main page. Secondly, the song reloads every time we go back to the page, which can absorb some serious download-upload from your Internet distributor if you visit the main page often in a single day.
I COULD, if you wish, show you what I mean for the whole week-end and let you experiment it. If you prefer it that way, I'll leave it to what it is right now. If you prefer the other one that I proposed, I'll change it again. Either way, it's easy enough for me to change the song every time.