The following extracts are from Calvin’s commentaries on the Bible.
On Psalm 33:2
It is evident that the Psalmist here expresses the vehement and ardent affection which the faithful ought to have in praising God, when he enjoins musical instruments to be employed for this purpose. He would have nothing omitted by believers which tends to animate the minds and feelings of men in singing God’s praises. The name of God, no doubt, can, properly speaking, be celebrated only by the articulate voice; but it is not without reason that David adds to this those aids by which believers were wont to stimulate themselves the more to this exercise; especially considering that he was speaking to God’s ancient people. There is a distinction, however, to be observed here, that we may not indiscriminately consider as applicable to ourselves, every thing which was formerly enjoined upon the Jews. I have no doubt that playing upon cymbals, touching the harp and the viol, and all that kind of music, which is so frequently mentioned in the Psalms, was a part of the education; that is to say, the puerile instruction of the law: I speak of the stated service of the temple. For even now, if believers choose to cheer themselves with musical instruments, they should, I think, make it their object not to dissever their cheerfulness from the praises of God. But when they frequent their sacred assemblies, musical instruments in celebrating the praises of God would be no more suitable than the burning of incense, the lighting up of lamps, and the restoration of the other shadows of the law. The Papists, therefore, have foolishly borrowed this, as well as many other things, from the Jews. Men who are fond of outward pomp may delight in that noise; but the simplicity which God recommends to us by the apostle is far more pleasing to him. Paul allows us to bless God in the public assembly of the saints only in a known tongue, (1 Cor 14:16.) The voice of man, although not understood by the generality, assuredly excels all inanimate instruments of music; and yet we see what St Paul determines concerning speaking in an unknown tongue. What shall we then say of chanting, which fills the ears with nothing but an empty sound? Does any one object, that music is very useful for awakening the minds of men and moving their hearts? I own it; but we should always take care that no corruption creep in, which might both defile the pure worship of God and involve men in superstition. Moreover, since the Holy Spirit expressly warns us of this danger by the mouth of Paul, to proceed beyond what we are there warranted by him is not only, I must say, unadvised zeal, but wicked and perverse obstinacy.
On Psalm 71:22
I will also, O my God! praise thee. … In speaking of employing the psaltery and the harp in this exercise, he alludes to the generally prevailing custom of that time. To sing the praises of God upon the harp and psaltery unquestionably formed a part of the training of the law, and of the service of God under that dispensation of shadows and figures; but they are not now to be used in public thanksgiving. We are not, indeed, forbidden to use, in private, musical instruments, but they are banished out of the churches by the plain command of the Holy Spirit, when Paul, in 1 Corinthians 14:13, lays it down as an invariable rule, that we must praise God, and pray to him only in a known tongue.
On Psalm 81:3
With respect to the tabret, harp, and psaltery, we have formerly observed, and will find it necessary afterwards to repeat the same remark, that the Levites, under the law, were justified in making use of instrumental music in the worship of God; it having been his will to train his people, while they were as yet tender and like children, by such rudiments, until the coming of Christ.
On Psalm 92:1
In the fourth verse, he more immediately addresses the Levites, who were appointed to the office of singers, and calls upon them to employ their instruments of music — not as if this were in itself necessary, only it was useful as an elementary aid to the people of God in these ancient times. We are not to conceive that God enjoined the harp as feeling a delight like ourselves in mere melody of sounds; but the Jews, who were yet under age, were astricted to the use of such childish elements. The intention of them was to stimulate the worshippers, and stir them up more actively to the celebration of the praise of God with the heart. We are to remember that the worship of God was never understood to consist in such outward services, which were only necessary to help forward a people, as yet weak and rude in knowledge, in the spiritual worship of God. A difference is to be observed in this respect between his people under the Old and under the New Testament; for now that Christ has appeared, and the Church has reached full age, it were only to bury the light of the Gospel, should we introduce the shadows of a departed dispensation. From this, it appears that the Papists, as I shall have occasion to show elsewhere, in employing instrumental music, cannot be said so much to imitate the practice of God’s ancient people, as to ape it in a senseless and absurd manner, exhibiting a silly delight in that worship of the Old Testament which was figurative, and terminated with the Gospel.
On Exodus 15:20
The beating of timbrels may indeed appear absurd to some, but the custom of the nation excuses it, which David witnesses to have existed also in his time, where he enumerates, together with the singers, “the damsels playing with timbrels,” (Psalm 68:25) evidently in accordance with common and received custom. Yet must it be observed, at the same time, that musical instruments were among the legal ceremonies which Christ at His coming abolished; and therefore we, under the Gospel, must maintain a greater simplicity.
On 1 Samuel 18: 1-9
In Popery there was a ridiculous and unsuitable imitation [of the Jews]. While they adorned their temples, and valued themselves as having made the worship of God more splendid and inviting, they employed organs, and many other such ludicrous things, by which the Word and worship of God are exceedingly profaned, the people being much more attached to those rites than to the understanding of the divine Word…