notes inégalesrefers to a performance practice, mainly from the Baroque eras, in which some notes with equal written time values are performed with unequal durations, usually as alternating long and short.

It was in France, beginning in the late 16th century, that notes inégales began to take on a critical role in performance practice. The earliest treatises that mention inequality of notes in performance indicate that the reason for this practice is to add beauty or interest to a passage which otherwise would be plain.

The typical rule, from the late 17th century, is that notes inégales applies to all notes moving stepwise which have a duration of one quarter the denominator of the meter, for instance, eighth notes in a meter of 2/2, or sixteenth notes in a meter of 4/4; and one half the denominator of the meter in cases of triple or compound meter, for instance, eighth notes in 3/4, sixteenth notes in 3/8, 6/8 and 9/8. In addition, the inégales could only function on one metrical level; for example, if sixteenths are to be played long-short, long-short, an even eighth-note pulse must be carefully maintained for the music to retain its shape.

Sometimes the notes inégales are notated as unequal,however it is uncertain whether this means to apply an even greater amount of inequality to dotted eighth-sixteenth note pairs than to eighth-eighth pairs, which are already understood to be played unequally. The exact amount of inequality required is also unspecified, and most of the treatises leave this detail to the taste of the performer. It may have varied from double-dotted to almost imperceptible, depending on the context.