Who were troubadours? What was their music like?

A troubadour was a composer and performer of Old Occitan lyric poetry during the High Middle Ages (1100-1350). Since the word troubadour is etymologically masculine, a female troubadour is usually called a trobairitz.

a French medieval lyric poet composing and singing in Provençal in the 11th to 13th centuries, especially on the theme of courtly love.