For Mozart, 1782 was a momentous year. He was working hard to establish a new musical career in Vienna after his abrupt departure from Salzburg. He was wrestling with his conscience, his father, the church, and the music establishment. And he was head over heels in love with Constanze Weber.

Mozart’s father was outraged, not least because Mozart had had a youthful romance with Constanze’s elder sister some five years earlier which had threatened to divert him from his work. Now here he was again, dismissed by Archbishop Colloredo of Salzburg, writing music for the theatre, revisiting the Weber family and paying court to the younger sister – who had turned out to be an enchanting young soprano.

With Leopold Mozart’s reluctant approval the couple were married in August 1782. Mozart had vowed to his father that if he was able to marry Constanze he would write a mass: a personal thanksgiving and statement of his devotion and religious conviction. He set about it free of the musical restrictions and liturgical demands of the Salzburg church authorities.

A Viennese tradition was evolving of a ‘concert mass’ in a customary format of six movements – much longer than Salzburg allowed. There were also the examples of Haydn and of Bach’s towering Mass in B Minor, written for performance rather than liturgical use. Mozart stepped into this tradition and the result was the Mass in C Minor.

It was also a declamation by Mozart of his mastery and a showcase for Constanze as the couple prepared for a return to Salzburg. Mozart wrote wheeling melodic arias, cadenzas and thrilling competitive duets for two sopranos and Constanze sang the lead.

Mozart wrote to his father in January 1783 saying that the work was ‘half-finished’. In July that year the couple arrived in Salzburg and set about seeking a first performance. This was arranged at the Abbey Church of St Peter on 26th October 1783. This was a Sunday and a saint’s feast day which may have helped to overcome the church’s limitations on time, but there remains doubt about what was actually performed. Manuscript fragments and shorthand sketches suggest that Mozart had been intent on developing a full six-movement setting with a series of movement endings of imposing fugues embracing great cadenzas – a device which apparently delighted Constanze.

However, only an incomplete setting of the Mass has survived – the Credo is partially complete and the final Agnus Dei movement is missing; this could be because it was not customary to sing it in Salzburg, although it is possible that an earlier setting was used. Whatever the reasons, what remains is a monumental work, matched only by his great Requiem and described by Alfred Einstein, foremost of Mozart’s biographers, as “his entirely personal coming to terms with God and his art, with what he conceived to be ‘true church music‘.”


The Kyrie is a long step from Mozart’s earlier settings; in sharp contrast, for example, with his Coronation Mass written three years earlier in Salzburg in which ‘Christe Eleison’ is allowed just two bars. The solemn choral ‘Kyrie Eleison’ leads to a soprano solo ‘Christe Eleison’ with gentle and appealing rises and falls over two octaves, which would have left no doubt of Constanze’s talents. Mozart developed this showpiece solo from a piano sketch which exists as a separate manuscript (‘Solfegio’ K 393).


Kyrie eleison.

Christe eleison.

Kyrie eleison.

Lord, have mercy.

Christ, have mercy.

Lord, have mercy.



Gloria in excelsis Deo

The Gloria is given six full sections instead of the single section of the earlier masses. In another of Mozart’s demonstrations of contrasting but interwoven styles, the triumphal ‘Gloria in excelsis’, with echoes of Handel, gives way to the gentle ‘Et in terra pax’.

Laudamus te

The second soprano is given a showpiece solo, again across a great range in a florid Italianate style.


The chorus is split into five-part harmonies, while violins and bass pursue a rhythmic dialogue.

Gloria in excelsis Deo

et in terra pax hominibus bonae voluntatis.

Laudamus te; benedicimus te;

adoramus te; glorificamus te.

Gratias agimus tibi

propter magnam gloriam tuam,

Glory be to God on high,

and on earth peace, goodwill towards men.

We praise Thee, we bless Thee,

we worship Thee, we glorify Thee,

We give thanks to Thee

for Thy great glory,


Domine Deus

The soprano soloists are now brought out for a joyous duet in a style reminiscent of Alessandro Scarlatti. Words, harmonies and rhythms are woven irregularly, never fully converging but sometimes only a beat apart.

Qui tollis

The chorus divides into a double chorus to deliver a dramatic chorale dialogue, with echoes of Handel in the strings.


The tenor joins the soloists for florid, syncopated variations of ‘Quoniam tu solus sanctus’.

Jesu Christe – Cum Sancto Spiritu

Mozart ends his Gloria with a short but imposing ‘Jesu Christe’ to introduce his mighty ‘Cum Sancto Spiritu’ fugue. Into it is woven the gentler ‘in Gloria Dei Patris’ and together they build to a dramatic climax.

Domine Deus, Rex coelestis,

Deus Pater omnipotens.

Domine Fili unigenite Jesu Christe;

Domine Deus, Agnus Dei, Filius Patris

O Lord God, heavenly King,

God the Father Almighty.

O Lord, the only-begotten Son, Jesu Christ;

O Lord God, Lamb of God, Son of the Father

Qui tollis peccata mundi,

miserere nobis;

Qui tollis peccata mundi,

suscipe deprecationem nostram;

Qui sedes ad dexteram Patris,

miserere nobis.

Quoniam tu solus Sanctus:

Tu solus Dominus:

Tu solus altissimus,

Jesu Christe -

Cum Sancto Spiritu,

in gloria Dei Patris. Amen.

Thou that takest away the sins of the world,

have mercy upon us.

Thou that takest away the sins of the world,

receive our prayer.

Thou that sittest at the right hand of God
the Father, have mercy upon us.

For Thou only art holy;

Thou only art the Lord;

Thou only art most high,

Jesus Christ,

With the Holy Ghost,

in the glory of God the Father. Amen.



Credo in unum Deum

Continuous but incomplete settings of this cheerful five-part chorus survive. The voice parts are complete but the parts for trumpets, drums and trombones have been reconstructed.

Credo in unum Deum,
Patrem omnipotentem,

Factorem coeli et terrae,

visibilium omnium et invisibilium.

Et in unum Dominum Jesum Christum,

Filium Dei unigenitum,

et ex Patre natum ante omnia saecula,

Deum de Deo; Lumen de Lumine;

Deum verum de Deo vero;

genitum non factum;

Consubstantialem Patri,

per quem omnia facta sunt.

Qui propter nos homines,

et propter nostram salutem,

descendit de coelis.

I believe in one God,
the Father Almighty,

Maker of heaven and earth,

And of all things visible and invisible.

And in one Lord Jesus Christ,

the only-begotten Son of God,

begotten of his Father before all worlds,

God of God, Light of Light,

very God of very God,

begotten, not made,

being of one substance with the Father,

by whom all things were made:

Who for us men,

and for our salvation

came down from heaven.


Et incarnatus est

The coloratura soprano performs with wind soloists leading to an inspirational interwoven cadenza. Mozart left a complete voice part but incomplete orchestration; the parts for strings have been reconstructed.

Et incarnatus est de Spiritu Sancto,

ex Maria Virgine:

et homo factus est.

And was incarnate by the Holy Ghost

of the Virgin Mary,

and was made man.



The double chorus works with woodwind and brass to establish the contrasting moods of the imposing ‘Sanctus’, the restrained ‘Dominus Deus’ and assertive ‘Pleni sunt caeli’, building to the eight-part ‘Hosanna in excelsis’ fugue.

Sanctus, Sanctus, Sanctus,

Dominus Deus Sabaoth.

Pleni sunt coeli et terra gloria tua.

Hosanna in excelsis.

Holy, Holy, Holy,

Lord God of Sabaoth.

Heaven and earth are full of Thy glory.

Hosanna in the highest.




The bass soloist joins the other solo voices for a contrapuntal setting of the ‘Benedictus, before the double chorus returns for a shorter version of the ‘Hosanna’ fugue.

Benedictus qui venit

in nomine Domini.

Hosanna in excelsis.

Blessed is he that cometh

in the name of the Lord.

Hosanna in the highest.


Composer:  Mozart Wiki Link: Title of Musical Work:  Mass in C Minor K427

London Concert Choir concerts featuring this musical work: