I have an old MP3 player that has a volume control, play/pause and skip in the earbud wires that go to a 3.5mm jack (but the earbuds have a 4-conductor plug). A

I have an old MP3 player that has a volume control, play/pause and skip in the earbud wires that go to a 3.5mm jack (but the earbuds have a 4-conductor plug). Also, the 4-conductor 3.5mm doubles as the USB port for uploading songs to it. You can also use normal 3.5mm headphones with it, you just loose the volume control functions.