meantone temperament
A historical tuning system used in Western music, especially for keyboard instruments, that tempers certain intervals to improve consonance.
Meantone temperament was often used for keyboard instruments in the Baroque period.
平均律 (equal temperament) is the modern standard tuning system that divides the octave into twelve equal semitones, while 中全音律 is a historical temperament that prioritizes pure major thirds.
The term is a Japanese calque of the Western musicological term 'meantone temperament'. 中 (middle), 全音 (whole tone), and 律 (temperament) combine to describe the tuning system's characteristic of tempering the whole tone.