RatioKey app for iPhone and iPad
4.4 (
3164 ratings )
Music
Entertainment
Developer: John Payne
Free
Current version: 1.1, last update: 7 years agoFirst release : 29 Aug 2010
App size: 315.59 Kb
RatioKey provides a dense selection of tones (105 over an adjustable 2-octave range), all related to the center (1/1) tone by frequency ratios composed entirely of low powers of the first five prime numbers (2, 3, 5, 7, & 11). Any two tones with frequencies related by a simple integer ratio constitute what is sometimes called a "pure" interval.