Temperament ordinaire

The expression occurs primarily in French-language works of the 17th and 18th centuries concerning theory and practice of musical intonation with regard to keyboard instruments.

[1][2] It is discussed again, in the same or a similar musical application, in modern literature concerned with historical practices relating to keyboard instruments and performance.

He did this by first recapitulating a conventional known temperament of his time, and then he compared that with his new scheme (which actually had been approximately conceived before, albeit without Huygens' mathematical precision); and he discussed the differences.

Huygens' description of the conventional arrangement was quite precise, and it is clearly identifiable with what is now classified as (quarter-comma) meantone temperament.

Accordingly, it does appear that for Huygens in 1691, 'temperament ordinaire' was a phrase denoting just the temperament in ordinary use, with no sign that he was using this expression as a proper or conventional name or label.

It appears from his description that Huygens believed that the ordinary tuning method then in common use was (quarter-comma) meantone temperament.

The two scales, both referred to as temperament ordinaire by Huygens and by Rousseau / Encyclopedie, have in common the degree of tempering applied to the fifths C G D A E .