A new quarter-tone piano has been created at The Sibelius Music Academy | Music News | Tiny Mix Tapes
Quarter Tone Chromatic Scale Sheet music for Piano (Solo) | Musescore.com
Charles Ives, Calvin Hampton, Donald Lybrert, Teo Macero - New Music in Quarter-tones for Chamber Ensemble and Two Quarter-Tone Pianos - Charles Ives, Calvin Hampton, Donald Lybbert, Teo Macero - Amazon.com Music
How to use Quarter-Tones
quarter-tone staff - new musical notation based on 24-tone equal temperament