Two things have recently happened: 1. I purchased a new amplifier that works with Airplay. 2. I changed my Iphone 4 to a Samsung Galaxy S4. Airplay works very well with the Iphone, but I'm having real problems getting it to work with my S4. The standard music player that comes with the S4 (just called 'Music') is compatible with Airplay, but it will only play the one song that the phone came preloaded with, called 'Over the Horizon' via Airplay. I've copied all my itunes songs over to my new phone, but when I want to play any of these songs via Airplay, it comes up and says 'unable to play'. I'm completely lost as to why it will play the song that came preloaded on the S4, but not the songs I copy over? They will play from the phone absolutely fine, both with and without head-phones, but just not via Airplay. Anyone has any ideas?