PHP help – decoding URLS

OK, So I have a nice script set up that outputs what’s playing in iTunes to a templated PHP page. And just for kicks, I made it so each Artist – Song Title links to allmusic.com’s search page.
Problem: AM.com doesn’t use %20, they use |. for example:
http://www.allmusic.com/cg/amg.dll?P=amg&opt1=1&sql=The%20Decemberists
http://www.allmusic.com/cg/amg.dll?P=amg&opt1=1&sql=The|Decemberists
So my question: How do i set the PHP script to output spaces as | instead of %20 ?