The majority of compositions written through the Middle Ages and into the Renaissance are by people long forgotten, and attribution often remains a problem.
In fact, it is not known who was responsible for the foundation works of Western classical music. Also unknown are the composers of many later songs, dance tunes, and marches that were integral to daily life and now also count as "classical." Early sacred music represented the official doctrine and aesthetics of the church; a composer's personal expression simply didn't count once the music was adopted for liturgical use, and, in many cases, it would have seemed presumptuous for an individual to take credit for a piece of sacred music. So although a very few specific medieval church composers, such as Hildegard of Bingen, are known, most early sacred music is the work of intentionally anonymous musician employed by the Catholic Church. In the realm of early secular music, a village musician might piece together a dance tune that became popular. Taken up by other players, the tune would pass by ear from village to village, and from generation to generation. The dance's origin would become obscure, even within the composer's lifetime. The rise of music publishing and commercial sale of scores in the Renaissance, and especially the Baroque era, began linking composers' names to their music. Yet some pieces were deliberately published anonymously for political or personal reasons, and many unscrupulous publishers simply neglected to name their composers, thereby avoiding the nuisance of paying them for their work. The survival of records from the Renaissance on has made it easier for musicologists to connect names to scores of debatable authorship written in the past four centuries or so. Yet scholars have sometimes been too quick to link a famous composer to an obscure composition and their attributions have often been dead wrong. Haydn's "Toy" symphony and Beethoven's "Jena" symphony, for example, turned out to be written by other composers. In some cases, crediting a score to "Anonymous" would remain the safest practice. Since the early twentieth century, the refinement of copyright laws, the availability of royalties, the rise of composer-advocacy groups, and cultural emphasis on individual achievement have all made it unlikely that any new work will appear without a solid attribution.