Add MS 29987 is a mediaeval Tuscan musical manuscript dating from the late fourteenth or early fifteenth century, held in the British Library in London. It contains a number of polyphonic Italian Trecento madrigals, ballate, sacred mass movements, and motets, and 15 untexted monophonic instrumental dances, which are among the earliest purely instrumental pieces in the Western musical tradition. The manuscript apparently belonged to the de’ Medici family in the fifteenth century, and by 1670 was in the possession of Carlo di Tommaso Strozzi; it was in the British Museum from 1876, where it was catalogued as item 29987 of the Additional manuscripts series. It is now in the British Library.