Music Thing Modular is a range of open-source electronic musical instruments designed by Tom Whitwell in London and manufactured in Brighton, England. Whitwell — a former journalist and magazine editor at Mixmag and The Face who later ran the Music Thing blog in the 2000s — got into DIY electronics through a Tom Bugs workshop in East London and became part of the wave of designers who helped build the modern Eurorack DIY scene around UK retailer Thonk.

The brand focuses on Eurorack synthesizer modules with a hacker-friendly, open-source approach, releasing schematics, code, and PCB files so builders can study and modify the designs. Notable modules include the Turing Machine, a random looping sequencer that became a cult favorite in the modular world, along with Radio Music, the Workshop Computer (a programmable 8HP module with program cards), the Startup headphone amp/mixer/clock, and the all-in-one Workshop System — a compact analog modular kit with 14 modules including oscillators, filters, envelopes, ring modulator, mixer, and a mini keyboard.

Music Thing Modular is closely associated with Thonk, the Brighton-based DIY synth shop that distributes most of the modules as kits. The brand is known less for high-volume manufacturing and more for inventive, idiosyncratic designs and a strong DIY/educational ethos, with workshops and detailed build documentation accompanying many releases.

Music Thing Modular has 12 products cataloged on Equipboard, including Modular Synthesizers and Synthesizers. Their gear is featured by 4 artists, with the strongest followings in Electronic, Pop, and Rock. Notable users include Andrew Huang, Joey Walker, and Surgeon.