Wasn't it Benjamin P. who wrote:

Is there any program that lets us send singles in to space? Because I
will like to be abele to send some maybe in many years to come some ET
my get the signal may be some one on another planet is doing something
like seti@home is doing. That will be something cool we could do I may
even help seti@home thanks and have a good day.

If you're quick, you can send a personal message to a star via Cosmic
Call 2004 at http://www.callyourstar.com/cosmiccall.html
(Unfortunately, you only seem to be able to do this as part of a package
which includes one of those name-your-own-star scams.)

Last year's Cosmic Call sent some music. It wasn't singles as such, but
a "pre-mix" of three tracks from an album by KFT.
http://www.teamencounter.com/missions/kft.asp

-- 
Mike Williams
Gentleman of Leisure