"Tuning Oscillator ONSA" is a musical reference pitch generator for vocal training and instrument tuning. It lets you play a reference tone for tuning by ear.

"Tuning Oscillator ONSA" can be generated a pitch tone on the scale from C1 to C8 based on the pitch of A4 (440Hz).
A desired reference pitch tone can be tuned between 420Hz and 460Hz in 1.0Hz unit.
In addtion, the musical tone can choose from four types, Tuning folk, Bell, Sine-wave and Piano.

Features:
- Musical tone generation on Twelve-tone equal temperament : C1 - C8
- Reference pitch adjustment : 440Hz +20/-20Hz in 1.0Hz unit.
- Plays reference tones with 4 selectable timbres. : Tuning fork, Bell, Sine-wave, Piano.
- Optimized for iPhone, Compact code size.

Applications:
- Vocal training.
- Musical instrument tuning.
- Various Music-related education and training.