Instead of a synth module - send the signal to a drum machine and let the Yamaha midi signal be the master. That way he can adjust volume and tone on the drum unit itself. I'm sure you can get a cheap drum machine for $50 or less. Heck, a brand new Zoom is only $100.
Write a pattern with just the chick sound.
Is it out of the question to send the whole signal to the drummer ...maybe from the HP outputs or the aux outs?