Not really no. The songlist is pretty much hardcoded into the game. You could get a different version though, or buy a J-PAC and break out the Stepmania...
You don't need a manual to do the most basic of troubleshooting on this. Audio starts at the RCA jacks on the 573 computer. From there you should be able to figure out where your left channel is getting lost. It may be something as simple as a loose connector.