Theriphone is a fun little app that turns your iPhone into a theremin - pitch, volume, vibrato, waveform mix and whether or not playing uses a chromatic or continuous scale can all be mapped to where you’re touching the screen, or to any of the pitch, yaw, roll and compass heading sensors, or acceleration.
How It Works
Theriphone has two oscillators, each of which can produce a musical pitch. Each oscillator can be on or off at any given time, at a certain loudness, and pitch (they do not have to be the same pitch!), using a combination of two waveforms, optionally with vibrato.
The sound they make is controlled by sensors built into your phone. You configure how they affect the sound. There are built in presets for how those sensors control the sound, and you can add your own. Those sensors are:
- Finger position - the app emits sound only when you are touching the screen. Oscillator parameters can be mapped to the vertical and horizontal position of your finger.
- Pitch, yaw and roll - the rotation of the phone in three dimensions (what your device uses to tell if it’s been turned sideways or laid down flat, to adjust the screen layout)
- Heading - this is your compass heading in three dimensions - want, say, vibrato, but only when you’re facing north? You can do that!
- Acceleration - this uses the accelerometer built in to your phone
To help get to know what each sensor does, the Theriphone app shows the value of each sensor on-screen.
What pitch and the characteristics of the sound are can be controlled by the motion and position sensors in your phone - an iPhone has pitch, roll and yaw sensors that detect how it is rotated in three dimensions, plus a compass and accelerometer - in addition to where on the screen you are touching in the vertical or horizontal axis.
For each oscillator, you can map the following settings to sensor input:
- Musical Pitch - set as musical notes from C0 to B8 - eight octaves!
- Amplitude - how loud the sound is
- Vibrato Intensity - how much the pitch varies
- Vibrato Speed - how rapidly the pitch varies
- Waveform - the mix of any two waveforms being combined: sine wave, triangle wave, hyperbolic sine, inverse hyperbolic sine, square, noise, or none at all (this has its uses)
- Chromatic Scale (on/off) - whether or not the note pitch should be continuous or step between notes in the chromatic musical scale
From musical uses, to wild and wooly sound effects, the Theriphone app has you covered!