Or you could play your backing track quite loudly near the zoom on a different device and play over it at the same time, thus recording both yourself and the backing track at the same time.
or you could play the backing track on a different device into headphones and play along, recording just yourself, but in perfect time with the backing track. You would then need some free software like Audacity on a PC to mix your backing track with the track of you playing.
I think GarageBand on iPad will allow you to play the backing track and record yourself paying at the same time.