"I'm always trying to give 'my' people access to anything that might prove too difficult otherwise." RJ
BIG Button (and/or switch) control of iPods, iPhones, smartphones, ANY Bluetooth device with music, using your own earbuds/headphones or your own speaker/dock (the BT version).
For older iPods with the 30 pin connector, I have the DOCK version.
If the user cannot press the buttons manually, consider the Additional Switch Inputs for each function they wish to control. Order Switch Inputs for that # of functions.