There is an analogy of form between the sound of people singing together and the unity to which the church aspires, and for this reason music is a particularly apt vehicle for worship. In Ephesians 5, it is in connection with the command to be filled with the Holy Spirit that Paul urges his readers to sing. Music offers a sounding image of the kind of diversified unity brought about by the Holy Spirit—“simultaneous voices which are nevertheless also one voice.” “There are many parts, but one body,” is how Paul expresses the same ideal in 1 Corinthians (12:20). It is by the Spirit that Christians are baptized into one Body (1 Cor. 12:13); but it is also the Spirit who gives diverse gifts (1 Cor. 12:7‐11)—who gives to each part of the body its special function, to each voice its distinct part in the great chorus.
—Stephen R. Guthrie, “Singing, in the Body and in the Spirit,” Journal of the Evangelical Theological Society 46/4 (December 2003), 644