It appears that the Sony HAP-Z1ES has a usb port so if acceptable by the owner of the Sony HAP-Z1ES anyone could bring music. One of the benefits of that style player. For me one of the best parts of these is the opportunity to hear new music.
With over 600 cds loaded already I'm sure I'll have something for everyone though.
Rhymes with rockin'!
Where does this take place? Is there more information somewhere?.