Magnificat

Whereas the structure of Dixit Dominus, Laudate pueri, Nisi Dominus, and Lauda Ierusalem is centered around reiterations of the psalm tone in each verse, the formal organization of Laetatus sum does not depends on the cantus firmus, but rather on the disposition of the text over a series of repeated bass patterns in the sequence ABACD ABACD’ AB’D’, where D’ is a variant of D. Each pattern corresponds to one of the eleven verse of the text except C and D, which combine for  a single verse. The Sicut erat, concluding the doxology, coincides with the final statement of the pattern D’. The psalm tone appears only occasionally in the tenor, altus, or cantus part, though normally stands out prominently when it does make an appearance.

The first of Monteverdi’s structural modules is the famous walking bass frequently cited in Montverdi literature. This bass is repeated exactly in each its five occurrences, lending Laetatus sum a strong sense of harmonic and structural continuity. The other three patterns, whose systematic return tightens the organization even further, have generally escaped notice.

The walking bass is both highly repetitive and sequential in its motivic structure. The second bass pattern is similarly repetitive. This pattern is reiterated almost exactly in its second statement, but is simplified in its final version.

The third bass pattern is almost completely static and serves as the support for virtuoso passage-work both times it appears. The only difference between its two statements is in the length of the sustained Gs. The fourth bass pattern is also repetitious, in that the final eight bars are a sequential replication of the preceding eight. this pattern is shortened through truncation and diminution in the second and third presentations (D’).

Patterns A and B each accommodate one verse of text, while C and D combine to present verses 4 and 8. The virtuoso passage-work over pattern C introduces each of these two verses, which then continue with a normal polyphonic texture over pattern D (or D’). D’ subsequently underlies the entire Sicut erat.

Although these patterns appear on the surface to be very different from one another, there are some importnt points of similarity among three of the four. A comparison between the beginning of the walking bass (A) and pattern B demonstrates that the later is a slower-moving variant of the former, particularly in its harmonic outline. Pattern D also features scale motifs similar to patterns A and B. Only pattern C, which is without any rhythmic or pitch motion at all, is radically different.

The structural sequence of these patterns, as schematized above, gives special prominence to the walking bass (A), which underlies all odd-numbered verses until the doxology, an arrangement reminiscent of the more primitive alternatim technique of psalmody. Since the underlying identities of each of the other basses are not obscured despite their varied repetitions, the entire psalm unfolds as a complex series of strophic variations, inspired perhaps by Monteverdi’s essays in strophic variations in L’Orfeo. In several of these, too, Monteverdi varied the bass-line in each successive strophe.

Monteverdi’s ingenuity in writing strophic variations is readily apparent in the manifold ways in which he manipulates the six voices, achieving continuous variety in texture and style as a counterbalance to the repeated bass. The walking bass sections (A), in where each successive statement of the bass supports progressively larger numbers of upper parts, illustrate this variety. Bass pattern B also supports varied textures and styles, ranging from a solo intonation to paired duets to imitative txtures. On the other hand pattern D normally underlies a full six-voice sonority, and the sustained pitch of pattern C supports virtuoso passaggi.

Unlike Laudate pueri, Laetatus sum does not have an elaborate Amen. Rather there is a simple plagal cadence to G with Picardy third, virtually identical to the plagal cadence concluding Dixit Dominus.

[Excerpted from The Monteverdi Vespers of 1610: Music, Context, Performance by Jeffrey Kurtzman. Oxford and New York: Oxford University Press, 1999]