This device looks very interesting. The information that I could get on say as Ondes Martenot, there is a left hand button to control the attack (volume) and the right hand ring controls the pitch of the note. It works only with a CV, vco, vcf, vac Qualibre external to 1V / October Single point of disappointment, the keyboard is fixed and not suspended like the keyboard waves that allows to make the ring without vibrato. So one has to do with a conventional keyboard. Despite of this weakness, it is much more accessible than Ondea (€ 20,000 outch) and I intend to buy one.