Agnus Dei: Bach's Mass in B minor

Context within work

From the last section of the B minor mass.
Solo aria followed by a chorus.
Alto solo, violin ritornello (low tessitura), low lying violin melody.
Obbligato aria: have to have instrumental line interlinking with solo voice: violin line essential.
The music's from one of his earlier works.
Old style of composition: elaborate.
Prima Prattical: first style; some harmonic features more elaborate.

1 of 8

"Agnus Dei, qui tolis peccata mundi, miserere nobis" translates to "Lamb of God, who takes away the sins of world, have mercy on us."
Minor tonality, starts in G minor. Opening 8 bars set therefore for these words.
Opening ritornello has lots of features which give it a lamenting feel.
Poignant intervals, eg diminshed 5ths (ex: F# to C) and uses diminished 7ths in violin ritornello.
Chromatic shapes also add to this feel.
Pairs of slurred quavers also. Sometimes appogiaturas.
Mostly syllabic setting apart from on the word: 'miserere' which is always melismatic. This is to add emphasis.
Opening vocal melody descends, giving it a depressing feel.

2 of 8

Ritornello melody uses some particular motifs.
1st melody has a disjunct, arpeggiated shape.
Uses some diminished 5th and 7ths throughout. Bach often used angular shapes/patterns, refers to wider scale of work.
Second idea (bar 3), uses slurred quavers, some of them being appogiaturas.
The rests in the continuo create a sigh like/sob feel.
vocal line: descends, long phrases, especially in bar 17 on the word: 'miserere'. It goes on.
The use of irregular phrase lengths makes it unsettling.
In places, vocal line quite linear, beginning tune: 'agnus dei'.
In other places, not so linear, lots of chromaticism, for ex: when the melody is in D minor (bar 27).
1st melody is sequential.
Lots repeated.

3 of 8

Starts in G minor.
Bar 27: D minor - dominant.
Bar 31: returns to G minor.
Examples of Dissonance (bar 1), also a chromatically altered chord (beat 4 of bar 1) -not what you'd expect.
A dissonance between C in violins and G in basso in bar 1.
Use of Neopolitan 6th, bar 2: Ab chord in 1st inversion.
Goes through D minor in bar 4, and C minor in the second half of bar 5.
Uses a full diminished 7th in bar 7.
False relations in bar 9, F followed by F#, in bar 14, Ab to A natural. Bar 18: E to Eb: typical of era.
Generally, more chromatic harmony.

4 of 8

Instrumental: 2 part texture. When voice comes in, it's a three part texture.
It's broadly a contrapuntal texture.
Bars 13, 14: imitation between voice and violin.
The violin obbligato imitates the voice.
A canon when the voice first comes in between the voice and violin obbligato. Canon at the 5th.
Bar 17: violins play ritornello from the opening melody against the melody in the voice.
Bar 31: repeats canon at the 5th.

5 of 8

6 of 8

Ritornello form: Bars 1-8 opening ritornello.
Bar 9: Vocal melody comes in: A section.
Bar 13: Ritornello in violin part.
Bar 17: move to D minor and ritornello material in violins. Very short ritornello in the middle of the aria.
Opening melody in bar 9 is repreised in bar 31.
Not as sectional as Laudamus Te, less ritornellis. But bar 23, 4 bars of Ritornello.
Integrated with voice, ritornello against it.
Bar 27: back to beginning melody but changes direction.
Bar 31: E minor
The structure has similarities with Laudamus Te but not such clear divisions between sections.

7 of 8

8 of 8