Touchscreen Electronic Instrument
Turn your phone into a theremin — the instrument you play without touching. Control pitch and volume with two fingers across a glowing touchscreen interface.
Phone Theremin divides your screen into two touch zones that work together — just like a real theremin, where one hand controls volume and the other controls pitch.
Left zone — Volume: Touch anywhere to activate sound. Slide up to increase volume, down to reduce it. Lift your finger to silence the instrument instantly — perfect for phrasing and articulation.
Right zone — Pitch & Vibrato: Slide up and down to move across a two-octave range (A3 to A5). Slide left and right to add vibrato depth. Scale markers show A3, E4, A4 (440 Hz), E5, and A5 as reference points.
Both hands on screen at the same time — that's when the music happens.
A focused instrument app — no ads, no accounts, no data collection.
Custom harmonic synthesis modelled on the original theremin timbre, with smooth portamento glide between notes and built-in reverb for that ethereal sound.
Slide horizontally in the pitch zone to add vibrato from none to full depth — the same expressive technique used by professional theremin players.
Record your performances as uncompressed WAV files. The iOS Share Sheet opens automatically so you can save to Files, share via Messages, or export to any app.
The interface adapts to both orientations. Landscape mode gives extra horizontal space in the pitch zone for more precise vibrato control.
No internet connection needed. Phone Theremin makes no network requests during operation. Your recordings stay on your device — always.
No analytics, no crash reporting SDKs, no advertising, no accounts. Nothing about you or your usage is collected or transmitted anywhere.
You'll be making music in under a minute.
iOS requires a tap gesture before any audio can play. Tap the ACTIVATE button to unlock the instrument and load the audio engine.
Touch anywhere in the volume zone on the left side of the screen. Slide up for more volume, down for less. The instrument is silent until both hands are active.
Touch the pitch zone on the right. Sound begins immediately. Slide up for higher pitch, down for lower. Drift left and right to add vibrato.
Faint horizontal lines mark A3, E4, A4 (concert pitch 440 Hz), E5, and A5 — two full octaves to explore. The note name and frequency display at the top in real time.
Tap REC to capture up to 30 seconds. The iOS Share Sheet opens automatically when you stop — save your WAV file to Files or share it directly.
No violence, no inappropriate content, no in-app purchases, no advertising. Just music.
Educator, technologist, and musician based in South Australia. Phone Theremin was built as an exploration of what a touchscreen can become — a genuine musical instrument that anyone can pick up and play.
gawain.duncan@mac.com