Westron Wynde is an early 16th-century song whose tune was used as the basis (cantus firmus) of Masses by English composers John Taverner, Christopher Tye and John Sheppard. The tune first appears with words in a partbook of around 1530, catalogued by the British Library as Royal Appendix MS 58.[1] Historians[citation needed] believe that the lyrics are a few hundred years older ('Middle English') and the words are a fragment of medieval poetry.