Ethero (App Store link) is a free app that turns your iPhone, iPad or iPod touch into a light theremin.
Ethero takes the amount of light coming into the device’s camera and translates it into a sound frequency. Moving your hand or another object in front of the device camera will change the pitch of the sound. The more light coming into the camera, the higher the pitch.
To control the volume of the sound, simply touch the screen of the iphone and move it up and down the screen.
- Calibration. To get the full frequency range of the instrument even when in poor lighting conditions. Press the cog icon, hold your device still then press the tick icon. If you want to reset the calibration, just press the cog icon again and press the cross icon.
- An LFO (low frequency oscillator) which adds vibrato to the sound. Press the ‘LFO on’ button to switch it on, and again to switch it off.
- A lock to chromatic frequencies. This makes the instrument easier to play if you’re just getting used to it, as only frequencies on the chromatic scale are played and the ‘glide’ from the sound is removed. Press the music-note button to switch to chromatic mode, and again to switch it off.