and while I do not have a guitar machine, per se, I do set my phone on the TD-17 shelf, (yup, it has a shelf for a phone), then bluetooth music thru the TD-17 and play along with it.

Also... here's a nice little feature.... at the gig we had sat down to eat and the lady who was in charge of the function came over and asked if we could play some music thru our PA during dinner.... soft dinner music.... our bass player, and main tech guy, immediately started searching for a way so I asked him, "Did you leave the main's on?"... he did.... so from my seat I chose a playlist, hit play, and it began playing over our PA... I had volume control, everything, right from my seat... didn't have to move.