A Moog Etherwave, assembled from a theremin package: the loop antenna around the remaining controls the amount though the upright antenna controls the pitch. If they don't seem to be locations of general public accommodation, and therefore are staff offices, then they are doing meet up with the elevator exemption https://emilianoneoeo.wizzardsblog.com/38384245/indicators-on-mezzanine-gate-you-should-know