Mellotronists

For those of you that played live with them...you pretty much have 
to leave them running so that when the parts of the songs come up in 
the act that utilize the Mellotron--it will be (hopefully) in tune. 
You get the fear that you need to *test* it off-cue to be sure it 
doesn't sound off when it's crunch time. I guess it would be nice if 
the motor locks on an exact speed immune from voltage fluctuations 
like a Tecnics turntable maybe things would be a bit more 
predictable...but that's really getting mechanical. 

I've used an Optigan on stage and these drifting problems keep your 
trigger finger on the pitch control on the first note. I've felt 
tempted to unplug the output jack & check it with headphones, but 
luckily the tenure of the band I play with doesn't exactly fret over 
nitpicking perfectionist details.