Jarp2600 wrote:Eer... Lemmetry: That beam is changing from note every 1/25 th second, so in fact it's monophonic, but it changes that fast, that you don't hear the changes?
Changes like that in electronics are barely noticable, but engineers still use small circuits to over come this tiny problem. I expect a Schmitt Trigger (great little thing that converts a fluctuating signal into digital (on/off)) would be used to stabilise this so that the gate signal is constant, not dipping every 1/25 of a second. (I doubt that on every 1/25 the signal goes completely off, it'll just dip. Otherwise, schmitt triggers wouldn't work in this case, but a monostable would (this converts a short trigger into a longer pulse, usually using a 555 chip).
Sorry if everyone's now baffled.
I don't see why you'd make it polyphonic, but it could be done fairly easily... I think.... If JMJ himself triggered off 2 notes "live" with the laser harp and they both played, then yes it is polyphonic. However, (long time since I've seen one in action) doesn't the laser harp have a couple of lasers to control things (octave up/down) or are these pedals? There's definitely a way of changing octave with the harp on its own, I've seen it in concerts.