The one genre to which Monteverdi applied himself with distinction but without competition from other enormously popular composers is the madrigal. Monteverdi wasn't the first or only great madrigal composer. The madrigal is a form of secular vocal music that flourished in the 16th and early 17th centuries. The earliest madrigals were published in Rome in 1530. Italy remained the home base of madrigal writing, although the form did spread around Europe and became especially fashionable in England.
Madrigals are perfect examples of polyphony.
Polyphonic music combines several simultaneous, more or less independent melodic lines and was the principal method of composing sacred and some secular music during Monteverdi's time. The opposite technique is called either monody, which is a solo song with some sort of accompaniment, or homophony-essentially the same thing, in which one voice leads melodically and is supported by chordal or slightly more elaborate accompaniment. Most l9th-century classical music and almost all contemporary popular songs are homophonic. Now, even though by the middle of the 16th century sacred music and secular madrigals were written polyphonically, there was no mistaking one kind of music for the other. Madrigals, on the other hand, were bursting with black notes - quarter and eighth notes, which are quite short.