Why is there music playing on my computer and how do I stop it?

Control Panel, Sounds and Audio Devices > check these settings to make sure theres nothing out of the ordinary selected here.

Check you program Startup

Start > Programs > Startup, Make sure theres nothing that automagically starts that you dont want.

This could be were you mysterious sound is coming from

Hope This Helps

Unless someone has set up a "scheduled task" in windows to start playing some music onyour computer at a scheduled time (do you have any brothers, sisters, friends who would have access to your computer to do this and who would actually want to goof up your computer?) then your system is likely infected with some sort of malware. But first check to see if there is a scheduled task to play music. If not, then do some system scanning for potential infection.

If you're on one of the recent Windows operating systems, and this is tied to logging in, you go to Sound in your Control Panel.

Then on the Sounds tab check things like Windows Logon to see what matches what you're hearing.