Chris Bonds:

>Pre-Haydn, composers did not use the triplet as a rhythmic figure in
>simple duple meter.

Check "Sanctus" (Bach's Mass in b minor).  It's written in common time
signature, but there is a continuous figuration of eight triplets (as in
12/8).  The strings draws a figuration of dotted eight + sixteenth, which
must be read as a quarter + eight triplet.

Pablo Massa
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