Paul!
RE: WOuld a guitar synth work with your JUNO.
Of coarse. But you'll still need a guitar, special pick-ups, a guitar synth or a Pitch to MIDI controller box. And of coarse you'll need to know how to play guitar.
I often use my GR33 to control synths like Ensoniq ESQ-M (rackmount ESQ-1), Yamaha TX816 and many more. I find that certain musical ideas that I come up with often hit me when I play guitar. Even though I'm a good keyboard player, I find that sitting down and trying to play the same idea on the keyboard can slow things down quite a bit. Especially if I have to use my brains to convert a bunch of typical guitar parts to a keyboard...
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-ED-