The MIDI wireline, which connects a computer to an external synthesizer
(or orchestrion), supports 1000 sequential note events per second, so
a chord of 30 notes takes 33 milliseconds (ms) to send.  To put this
in context, the pneumatic or solenoid player action in the instrument
adds anywhere from 30 ms to over 100 ms additional delay, depending on
the intensity.

Many simple external synth devices, and probably some older solenoid
pianos, will be overloaded with a command to play a 30-note chord!
My Roland 250s keyboard synth piano (1980s design) plays only 16 notes,
and I can hear a definite improvement if I arrange the MIDI data so that
the 16-note chord is sent in sequence from bass to treble notes.  More
modern synths have faster microprocessors and so the difference isn't
as pronounced.

But only the MIDI wireline is subject to the limitation of 1000
events per second.  Instruments with a self-contained floppy or hard
disk drive can send the commands virtually instantaneously, mere
microseconds apart, limited only by the speed of the microprocessors.
This is why a critical listener can discern a slight degradation when
a Disklavier is played from an external data source via the MIDI
wireline, compared to playing using its built-in floppy drive.

A similar effect may be apparent using the PowerRoll, which gets data
via the MIDI wireline.  I invite users of the PowerRoll to report on how
the PowerRoll performs compared with the same song on paper music roll
played on the same piano.  Then we will have experimental evidence to
discuss, at least for pneumatic instruments controlled by MIDI wireline.

Robbie Rhodes