donpatt,
You cannot "play" registration files directly from an external media. Registrations are "settings" which once loaded instruct the keyboard on settings for a particular performance (which could includes styles used, voices, wave/mp3 player ... etc).
Copy your registrations on the USB stick into the Registraion folder of AUDYA's Hard Drive. Next, press the REGISTRATION button on AUDYA and that will automatically take you into the Registration folder from which you can select and load your settings for your songs!
Hope this helps.
Thanks,
AJ
PS: Registration files have to be those creaed on an AUDYA series keyboard!
[This message has been edited by Ketron_AJ (edited 09-20-2010).]