Roland de Lassus (Orlando di Lasso), musician and composer of the 16th century, is one of the masters of 16th century polyphony, considered by many to be the most versatile.

The collection consists of 24 bicinia, or compositions for two unaccompanied voices or instruments, a genre which came into being in the first half of the XVI century, clearly aiming to teach polyphonic composition. The collection includes 12 on a sacred Latin text while the rest has no text.

This music was composed in the mature years of Lassus, during the time when he was employed by Duke Albert V of Bavaria, where he was an esteemed choir master and when he undertook regular journeys to Italy.