I will sacrifice in the tent of Jehovah sacrifices of shouting, I will sing, yea, I will sing praises unto Jehovah (Ps. 27:6), where by "tent" is expressed what is celestial, and by "shouting" "singing" and "singing praises" what is spiritual thence derived. Again:

Sing unto Jehovah, O ye righteous, for His praise is comely for the upright; confess ye to Jehovah on the harp, sing unto Him with the psaltery, an instrument of ten strings. Sing unto Him a new song, play skillfully with a loud noise; for the Word of Jehovah is right, and all His work is in the truth (Ps. 33:1-4), denoting the truths of faith, concerning which these things are said. [2] Spiritual things, or the truths and goods of faith, were celebrated with the harp and psaltery, with singing and analogous instruments, but the holy or celestial things of faith were celebrated with wind instruments, such as trumpets and the like; and this was why so many instruments were used about the temple and so often, in order that this or that subject might be celebrated with certain instruments; and in consequence of this the instruments came to be taken and understood for the subjects that were celebrated with them. [3] Again:

I will confess to Thee with the psaltery, even Thy truth, O my God; unto Thee will I sing praises with the harp, O Thou Holy One of Israel; my lips shall sing when I sing praises unto Thee, and my soul which Thou hast redeemed (Ps. 71:22, 23), where also the truths of faith are signified. Again:

Answer to Jehovah in confession, sing praises upon the harp unto our God (Ps. 147:7) "confession" has respect to the celestial things of faith, and therefore mention is made of "Jehovah;" and to "sing praises upon the harp" has reference to the spiritual things of faith, wherefore "God" is spoken of. Again:

Let them praise the name of Jehovah in the dance, let them sing praises unto Him with the timbrel and harp (Ps. 49:3), where the "timbrel" signifies good, and the "harp" truth, which they praise. [4] Again:

Praise God with the sound of the trumpet; praise Him with the psaltery and harp; praise Him with the timbrel and dance; praise Him with stringed instruments and the organ; praise Him upon the loud cymbals; praise Him upon the cymbals of shouting (Ps. 150:3, 4, 5). These instruments denote the goods and the truths of faith which were the subjects of praise; for let no one believe that so many different instruments would have been here mentioned unless each had a distinct signification. Again, referring to the knowledges of good and truth:

O send out Thy light and Thy truth, let them lead me, let them bring me unto the mountain of Thy holiness, and to Thy habitations, and I will go in to the altar of God, unto God, the gladness of my exultation; yea, I will confess unto Thee upon the harp, O God, my God (Ps. 43:3, 4). [5] In Isaiah, referring to the things that are of faith, and the knowledges thereof:

Take a harp, go about the city, play well, sing many songs, that thou mayest be called to remembrance (Isa. 23:16). The same is expressed still more plainly in John:

The four animals and the four and twenty elders fell down before the Lamb, having everyone of them harps, and golden vials full of incense offerings, which are the prayers of the saints (Rev. 5:8), where it must be evident to everyone that the animals and elders had not harps, but that by "harps" are signified the truths of faith, and by "golden vials full of incense offerings" the goods of faith. In David the performances on the instruments are called "praises" and "confessions" (Ps. 42:5; 69:31). And in another place in John:

I heard a voice from heaven as the voice of many waters, and I heard the voice of harpers harping with their harps, and they sang a new song (Rev. 14:2-3). And in another place:

I saw them standing by the sea of glass having the harps of God (Rev. 15:2).It is worthy of mention that angels and spirits distinguish sounds according to their differences with respect to good and truth, not only those produced in singing and by instruments, but also those of voices; and they admit none but such as are in accord, so that there may be a concord of the sounds, and consequently of the instruments, with the nature and essence of the good and the true.