The Magnificat is a ‘canticle’, a non-metrical, song-like passage of text drawn frombooks of the Bible other than the Book of Psalms. The Magnificat – the Song of the Blessed Virgin Mary – comes from the Gospel of St Luke, 1:46–53, and represents Mary's joyful response to the message given her by the Angel Gabriel that she was to bear the son of God. In the Catholic liturgy this canticle was set to be read or sung daily towards the end of the main evening Offce of Vespers. It forms the climax of the service, and while it is being sung a priest censes the altar. The Magnificat is preceded by the singing of an antiphon specific to the particular day on which it was being performed, and followed by the ‘Gloria Patri’ and a repetition of the antiphon. This whole unit is then followed by a prayer and the dismissal of those who have celebrated Vespers.

The text of the Magnificat is laid out in the Liber Usualis (an abbreviated compendium of texts and music for the Mass and Offce) as follows. (The English version is the one given in the Book of Common Prayer.)

It is now more than twenty years since the appearance of The New Monteverdi Companion, edited by Denis Arnold and Nigel Fortune, to whom this book is dedicated. During those years the re-evaluation of Monteverdi and his work by performers and historians alike has proceeded apace and shows no sign of abating. New generations of performers now work comfortably with the instruments of Monteverdi's day and continue to explore the types of vocal production with which he might have been familiar; and listeners can now experience a wide range of live and recorded interpretations of Monteverdi's music. More is known now about the context in which Monteverdi worked, and fresh questions have been asked about his musical output, not least those arising from the so-called "New Musicology". On his operas alone three new books have appeared within the last five years.

Monteverdi's appointment in 1613 as maestro di cappella of S. Marco, Venice, brought him financial security in a post that also allowed him a good deal of freedom to accept commissions elsewhere, both in and outside the city. His initial salary of three hundred ducats was raised by the Procurators of S. Marco to four hundred in August 1616,1 making him, in his own words

Monteverdi's reference here to his assistant choirmaster is a reminder that he was not alone in shouldering the responsibilities of providing music for S. Marco. He inherited, and was later able to appoint, assistants who were not only performers, but also able composers of sacred music – Marc'Antonio Negri (singer and assistant choirmaster from 1612), Alessandro Grandi (singer from 1617, assistant choirmaster from 1620) and Giovanni Rovetta (singer from 1623, assistant choirmaster from 1627).

This guide to Monteverdi's music is constructed in three sequences. The first is a catalogue of Monteverdi's works, both surviving and lost, in as near as possible date order, followed by a list of undated manuscript sources. In the case of sources containing more than one work, the contents of the volume are listed in the order in which they appear in the earliest, or the only, source (this order is not always followed in later and modern editions – see Chapter 3, above). The second sequence is a catalogue, by short title only, of prints and manuscripts containing contrafacta of Monteverdi's music: that is, adaptations of his settings by a different author to texts that are usually sacred or spiritual in character (the first lines of these settings are given in the Index). The third sequence is an index of first lines and titles, which serves as an index both to the catalogue and to the discussion of individual works in the text of this book. Each work can be traced in the catalogue from the index through an identifier, which includes the date of publication or first performance, or the year(s) in which a work, now lost, is discussed in Monteverdi's letters or another source; manuscripts are identified by the sigla for the library in which they are located. Dates or library sigla followed by [CF] refer to contrafacta. Dates followed by a superscript number follow the convention found in RISM (Répertoire international des sources musicales, the International Inventory of Music Sources), specifically in the volume Recueils imprimés XVIe-XVIIe siècles (Munich-Duisburg, 1960).

Monteverdi's comment that the Vespers settings and sacred concertos were ‘suited to the chapels or chambers of princes’ indicates that he expected his music to be performed by the expert singers and instrumentalists employed at a court like Mantua or at major churches like St Peter's, Rome, or St Mark's, Venice, or perhaps in one of the musical establishments presided over by a cardinal. And since court and Church were the major employers of professional musicians in the late Renaissance, such establishments would have included the finest performers of the day. The sacred concertos of the 1610 print were certainly designed to show off the accomplishments of such performers, and the styles and techniques that they exemplify range from wellestablished traditions of vocal and instrumental virtuosity to the most up-to-date rhetorical styles of Florentine continuo song and opera.

Virtuoso singers were highly prized in court circles, the best of them receiving much higher payment than the composers who supplied them with music. Unlike the star singers of today, however, whose voices are trained to produce a rich, dark, powerful tone that can be projected over a large orchestra, virtuosos of Monteverdi's day cultivated lighter and more flexible voices with the ability to articulate notes very rapidly in the throat. This last ability was particularly important since they were expected, especially when singing solo, to grace the lines that they sang with ornate and technically difficult improvised ornamentation; and their ability to do this was one of the most admired aspects of their art.