Believe it or not, sound is a bit of a controversial subject when it comes to web sites. It's difficult to use sound properly, and it usually makes a site annoying to visitors.
I've rarely seen a site which uses sound in a good way. Now this excludes those sites that just list sound files - that's not using sound, that's just listing some files which people can download.
How many websites have you visited which immediately start up some strange or obnoxious background sound? As a matter of fact, including a background sound on virtually any site is a great way to chase away visitors. I've never met anyone who liked background sound (except for some webmasters).
If you feel you must include background sound (perhaps for a MIDI or music site), then please, please include an easy, obvious way to turn it off. You will make your visitors happier.
There are quite a few sound formats to choose from. You need to be careful to choose formats which your visitors can listen to - if you choose some strange formats than your music cannot be heard by everyone. And that chases away visitors. What's almost as bad is requiring plug-ins - that chases away visitors pretty fast also (except for real audio, which is an accepted format).
Some of the formats which you can use are listed below.
Unless otherwise noted, all photos and text is Copyright © Richard G Lowe, Jr.