24-tet scale on C (50 cent steps). Easley Blackwood, Jr.'s notation for 24 equal temperament. As only "ups" are used, there are no three-quarter flats and quarter flats are enharmonically spelled (Dd = C#↑). Pitches are split into two groups of 12. MIDI pitch bend is correct for intervals.
A sound file playing the interval of an augmented fifth, in equal temperment. The first tone is a sine wave at 300 Hz, the second is at 476.1 Hz, the last is the interval. Made with NCH Tone generator.