I'm looking for a guitar accessory, but I honestly have no clue what it's called.?

What's confusing people is that you're saying you can record a beat, then play over it... well, a guitar doesn't play the beat, that would be the drum section. Maybe you're talking about a beat box or drum machine, where you can create a beat, then play along with it on your amp?

If you're not talking about drums, then you might be referring to a loop station for a guitar, where you record a rhythm track, it plays it in a continuous loop, then you can play lead over the top.

Sounds like you're looking for a small, portable multi-track recorder. Several companies make them, including, Boss, Tascam, and Korg.

Look here: http://elderly.com/accessories/cats/REC.html

Ya i comprehend what your speaking approximately in spite of the shown fact that it wont precisely silence it quite is going to easily have an acoustic sound whilst interior the earpiece it sounds electric powered. you need to maximum probable get one at Guitar center or Sam Ash

Sorry, but I can't seem to think of anything like that.. why don't you just find out where he got it from and see if the people there know what it is?

Im not exactly sure this it what you are thinking of but its called a metronome. it keeps a constant beat while you are playing.