I found that I can search for a song term like so:
https://itunes.apple.com/search?media=music&entity=musicTrack&attribute=songTerm&term=xxxx
But what I really want to do is search by song title and the artist. I can't seem to find syntax that would allow for that. Is it possible? I'm doing this from inside an iOS audio streaming application so I want to keep the returned results as small as possible so as to not use up much of a person's data plan.