Did John Calvin discourage harmonies in congregational singing?

Yes, he opposed the use of harmony in public worship as being not “one voice”.

See: Protestant Church Music: A History by Walter Blankenburg, pp. 516-517, Edited by Friedruch Blume. New York: Norton & Company, 1974.

This bibliography of mine is pretty extensive as well, Google doc click here.

What an intriguing question! Here's an intriguing quote from Doug Floyd:

"You don’t get harmony when everybody sings the same notes."

What would John Calvin have made of that? The point is that harmony can sometimes wrongly be mistaken for uniformity. In music, there may be total uniformity with different singers and/or players sticking to the exact same notes, bleating out the same tune. But for musical harmony, you must have a variety of complementary notes being sung (or played) at the same time!

The situation in the Middle Ages was that in Catholic worship the liturgy was almost entirely restricted to the celebrant and the choir. The congregation only joined in a few responses in the vernacular. Luther so developed this element that he may be considered the father of congregational song. Portions of the liturgy were converted into hymns, the Creed and the Sanctus. Yet Calvin could hardly be said to have been reluctant to accept congregational singing given that:

In 1524, Theodore de Beze introduced congregational psalmody to the German-speaking Calvinist churches in Strasbourg where he was pastor. In 1533, Calvin presented the Genevan Psalter that was followed by the editions of 1542, 1551. When Calvin became the pastor of the French-speaking congregation in Strasbourg in 1538, he introduced the French Psalter that was later published in its complete form in 1562. Clement Marot and Beza, the latter Calvin’s eventual successor at Geneva, translated the texts from the psalms, with Loys Bourgeois composing the melodies using a simple chord style. Calvinist congregations sung the metrical psalms unaccompanied and in unison.

The quote you provide about a reason for Calvin objecting to harmony singing being "violating the unity of the body" hardly makes sense given the Pauline passages about all the different parts of the body being needed to make the body (i.e. the Church) function! Paul shows how ludicrous it would be for the foot to say to the hand it did not belong to the body. "But in fact God has arranged the parts of the body, every one of them, just as he wanted them to be. If they were all one part, where would the body be? As it is, there are many parts, but one body." - 1 Corinthians 12:14-20 Violating the unity of the body only happens when the diversity of the body is denied! Calvin would have known that, and the parallels that can be drawn with the church worshipping God together musically are striking.

Calvin was not a person gifted in art or music, as was Luther, and that appears to account to a major extent for their different approaches to music in the congregation.

Unfortunately, Calvin was not motivated to promote a legitimate use of music. And unlike Luther he did not require would-be-pastors to pass a musical test before they could be accepted for ministerial training. That Luther did, and because his young men went on to start and to pastor churches all over Germany, and then throughout much of Europe, partly explains the early and rapid proliferation of the Lutheran style of music when no such comparable development took place among the Calvinist churches.

However, in the article from which the above two quotations are taken, it only says Calvin took a firm stance against the use of musical instruments for Psalm-singing. It does not say he took a stand against vocal harmonies amongst the singers in the congregation. There is only that one tiny sentence where singing in unison is mentioned, which is not the same as saying harmonies were disallowed, or even discouraged.

On that point the observation might be worth making that, anywhere in the world where a few people get together and sing, harmony singing will be lacking amongst those who are fairly musically illiterate. It takes a certain minimum standard of musical knowledge, training and appreciation to get several people to sing harmoniously, in parts. If a congregation has never learned how to do that, it will take a brave individual indeed to start singing harmonising notes the congregation has never heard before! Usually, the more unmusical a congregation is, the more likely they are to feel comfortable sticking to unison singing. That may have more to do with the lack of harmony singing in some congregations than anything Calvin might have said centuries ago about the matter!

The second and third quotes are to be found in http://thirdmill.org/newfiles/joh_barber/PT.joh_barber.Luther.Calvin.Music.Worship.pdf from the Reformed Perspectives Magazine article by John Barber, PhD, 'Luther and Calvin on Music and Worship' (Volume 8, Number, 26, June 25 to July 1, 2006). This article is full of references to other related sources, so I recommend you search it for more information.

Did John Calvin discourage harmonies in congregational singing?

He did not discourage congressional singing, but it seems that John Calvin did discourage congressional singing in harmony.

In the area of church music, Zwingli, although an amateur musician himself, had not set down any of his ideas of congregational singing. Calvin, however, was well aware of the power of music and soon stated his ideas "in. Keeping with the austere simplicity of his religious views."(Re p.J58) He referred to St. Paul as his authority in advocating the singing as well as the reciting of the psalms, and he permitted no other texts to be used for this purpose. In keeping with his views that the psalms should be understood by the congregation, he adopted the use of French translation, in verse. He found no objection to singing these and other psalm adaptations to German melodies borrowred from the Lutherans. His main stipulation in regard to a melody was that it should be the equal of the text in majesty. (Re p.J59)

Luther demanded of church song that it should be predominantly (but not exclusively) congregational, that it be in the vernacular, and derived from scripture, so that through the medium of song, the Word of God might remain among the people. Unlike Calvin, Luther had no objection either to the traditional Catholic chant or to contemporary part-music. Calvinists on the other hand, steadfastly refused to countenance any of the trappings and ceremonies of Romanism.(Sc xvii) They, too, insisted on the uses of the vernacular and, with the same motive they avoided such musical elaborations as tended to make difficult the understanding of the words being sung or to distract attention from these by linking them with polyphonic settings which openly displayed vocal skill, appreciation of which they regarded as a species of sensual enjoyment.

Calvin states his idea of the role of singing and of the danger of distraction in Book III of the Institutio, (chapter 20, sections 31 and 32):

"It is fully evident that unless voice and song, if interposed in prayer, spring from deep feeling of heart, neither h9.s any value or profit in the least with G:od. But they arouse his wrath against us if they come only from the tip of the lips and from the throat, seeing that this is to abuse his most holy name and to hold his majesty in derision.

Yet we do not here condemn speaking and singing but rather strongly commend them, provided they are associated with the heart's affection. For thus do they exercise the mind in thinking of God and keep it attentive , unstable and variable as it is, readily relaxed and diverted in different directions, unless it be supported by various helps. Moreover, since the glory of God ought, in a measure, to shine in the several parts of our bodies, it is especially fitting that the tongue has been assigned and destined for this task, both through singing and through speaking, For it was peculiarly to tell and proclaim the praise of God. But the chief use of the tongue is in public prayers, which are offered in the assembly of believers, by which it comes about that with one common voice, and as it were, with the same mouth, we all glorify God together, worshipping him with one spirit and the same faith. And we do this openly, that all men mutually, each one from his brother, may receive the confession of faith and be invited and prompted by his example.

And surely, if the singing be tempered to that gravity which is fitting in the sight of God and the angels, it both lends dignity and grace to sacred actions and has the greatest value in kindling our hearts to a true zeal and eagerness to pray. Yet we should be very careful that our ears be not attentive to the melody than our minds to the spiritual meaning of the words.

Such songs as have been composed only for sweetness and delight of the ear are unbecoming to the majesty of the church and cannot but displease God in the highest degree." (Ca pp.894 and 895) - John Calvin and music: the rise of protestant psalters in the sixteenth century

Tim Montgomery goes on to say:

Bourgeois favored part-singing. Calvin did not. His opposition not only ultimately dismayed Bourgeois so much that he left Geneva in 1557, but the use of unaccompanied melodies characterized the Reformed singing of the Psalms, in most places, for centuries. (Ge p.?4)

In spite of Calvin's opposition to harmonization, four part settings were made by Bourgeois in 1547. His latest known publication (1561) included settings a 4, 5, and 6, described as suitable for instruments as well as voices, of eighty-three of the melodies he had arranged at Geneva. While none of his harmonic versions found permanent acceptance, his melodic settings influenced the harmonization of other composers, especially Goudimel.

Ca, pp. 894-895: Calvin, John. "Institutes of The Christian Religion." translated by Ford Lewis Battles. The Library of Christian Classics ed. by John T. McNeill. Vol.'s XXI and XXII, (Philgdelnhia, The Westminster Press,Vol. XXI,1960, Vol.XXII, 1954.)