5-limit

The 5-limit (aka pental) consists of all ratios in just intonation whose ratios contain no prime factors greater than 5; for example 5/4, 16/15, and 81/80. The 5-limit is considered the basis of western harmony, with the ratios of the 5-odd-limit being considered consonances. The main consonant chords of the 5-limit are the 4:5:6 major triad and the 10:12:15 minor triad. The smallest EDOs that approximate this these triads within 20 cents are 12, 15, 19, 22, etc.

Aberrismic theory

Main article: Aberrisma#Quasi-diatonic aberrismic scales

The fundamental pental aberrismic scale is blackdye.