2 - E-mu Systems Proformance/1 midi grand pianos. 2- half-rack, 16-bit true stereo piano modules, which gives you 32-note polyphony.
Connecting a second Proformance module to the first's MIDI Out, the latter automatically switches to MIDI Overflow mode, which means that as soon as its 16-note polyphony is exceeded it sends subsequent notes to the second Proformance (in fact, this is the MIDI Out's only function). Consequently, two modules will give you up to 32-note polyphony.