here’s how to connect a YAMPP III industrial MP3 Player to an Arduino Board.
and here’s how to get the serial data in via an easy radio module. the arduino just remembers which song has been played and prevents it from being played again. i do it this way, because the “stations” will repeatedly send out the byte for their Audiofile, and the yampp would start to play the song every time it receives the signal.
download the code here: CrossEasyradio.zip