The tELHARMONIC music synthesizer module is a Multi-Voice, Multi-Algorithm synthesizer module named for the music hall considered by some to be the location of the first electronic music concerts. It was coded by Tom Erbe with the goal of presenting three historically important pioneering electronic tone generation techniques less often implemented within the modular synthesizer.

The tELHARMONIC's roots go back further than the advent of electronic music, as it also takes a new approach to handling music theory in the modular context. TONIC, INTERVAL, DEGREE and D-GATE, allow for patch-programming of complex chord progressions, scales, melodies and playing styles. This Voltage Controlled Music Theory guides the Algorithms in a unified way, whereas CENTROID, FLUX and H-LOCK sculpt the timbre of each Algorithm uniquely, allowing for complex sounds to be created around a unified melodic structure and pattern.