So here's the easy way
First, upload or find the URL of the music file that you wish to play in the background.
Once you've uploaded your music file - pulp.mid in this case, just paste the following code into your page. (Just go to the right bottom corner of the screen and click on 'edit html' : once there, just paste the code.)
(Click on the image if it is unreadable - I would have used text, but blogger also has a similar code, so it'll just disappear..)
Its possible to embed anything using this code, not just music. Once the first line is written, you can write html code normally.
N.B. : It is advisable to put this code at the bottom of your page, so that you can use the googlepages interface with greater ease.
This is twenty per cent skill. Adios Amigos!