A lai (or lay lyrique, "lyric lay", to distinguish it from a lai breton) is a lyrical, narrative poem written in octosyllabic couplets that often deals with tales of adventure and romance.
The terms note, nota and notula (as used by Johannes de Grocheio) appear to have been synonyms for lai.
This distinguishes the lai from other common types of musically important verse of the period (for example, the rondeau and the ballade).
Towards the end of its development in the 14th century, some lais repeat stanzas, but usually only in the longer examples.
The lai reached its highest level of development as a musical and poetic form in the work of Guillaume de Machaut; 19 separate lais by this 14th-century ars nova composer survive, and they are among his most sophisticated and highly developed secular compositions.