Glosa is a term that was often used by Spanish musicians in the 16th century to mean: a piece of music which was similar to a set of variations. Composers at that time often wrote collections of glosas. The term is related to the word “gloss”. They were comparing it to gloss (ornamentation) that a poet might put on his poem. They were often on religious themes.

Antonio de Cabezón was an important composer of glosas.