Returns an array of songs whose artist, album or song name match the given string.

The search string is broken up into individual terms, so <tt>'pink moon'</tt> will match all tracks on Pink Floyd's The Dark Side of the Moon and 'pink moon gig' will match "The Great Gig in the Sky."

Sends add_time_and_size() to each of the songs.

• return: an array of Songs

• string $search_term: the search string