Ludus Danielis (The Play of Daniel) is a medieval mystery play that originated in Beauvais in the north of France; it was copied around 1230 into a manuscript now in the British Library, Shelfmark GB-Lbl Egerton ms. 2615. Many scholars who have edited the Ludus Danielis feel that the work belongs to the middle of the twelfth century or possibly even a little earlier; though Grove's will not place it beyond the early thirteenth. No matter what the actual date, the Ludus Danielis is one of the earliest and most detailed musical medieval plays in existence. Given with some indications of instrumentation and stage action, the Ludus Danielis still plays well in the twenty-first century; it has been revived numerous times, first famously by Noah Greenberg with the New York Pro Musica in 1958. Greenberg's transcription was published in 1961, and several others have followed.

Mystery plays were crude pageants staged by monasteries and trade guilds in medieval times, both to entertain and to provide instruction about the content of some biblical stories; they were aimed at townspeople, not the nobility. As the Bible had yet to be translated into any vernacular languages and services were conducted primarily in Latin, the mystery play was an immediate method through which the ordinary person could get a sense of the content of the Bible. Although music was part of the usual mix of a medieval mystery play, the music in Ludus Danielis was considered significant enough to write down. Interestingly, this particular play was acted by neither tradesmen nor monks, but by monastic students in Beauvais; performances were annually given either around New Year's or during the Feast of Fools. Its concluding hymn, "Nuntium vobis fero," is liturgically linked to Christmas; none of the music or text of the rest of the play has been located in independent sources.

The play illustrates three episodes from the biblical Book of Daniel; his readings of the writing on the wall at Belshazzar's feast, his escape from the lion's den and his messianic prophecy. The original work contains about 50 distinct melodies, but the division of numbers and scenes varies based upon whose edition is in use; improvisation, pieces added from other sources, and other additions are commonly found in modern stagings of the Ludus Danielis. The source, taken with no additions, runs about 40 minutes all told, but with added material Ludus Danielis can run more than an hour and, in the realization by the Harp Consort, takes nearly 80 minutes.

© Uncle Dave Lewis, All Music Guide