Originally posted by jimye
any idea how anyone?
You're not going to want to do this. Stick to tapping in the tempo yourself. If you're drummer is wavering just wander over and re-sync ever so often with a few taps. For a lot of reasons sync'ing with a drummer's actual kick is a bad idea. High on the list is that few drummers actually place their kicks *on* the beat. It would feel pretty cold and sterile if all their kicks fell precisely on the beat. "Feel" is about moving it slightly to one side of the beat. Also high on the list is that they might not be giving you a 4 kicks per bar. Might be 2 in one, 1 in another, 3 after that. So you'd end up with the tempo entered arhythmically.
This is the downside to using tap tempo with continuous effects like tremolo. Unlike delay, where you tap in the tempo but ultimately control when the repeats happen by playing (or not playing), trem and the MuRF run continuously. So a slight mis-tap begins to get exaggerated over time. Really want you want to do is have the drummer play to your effect.