In the chapter on music, Dever and Alexander argue against choirs, since "we have no example of a church choir in the New Testament—the Bible never represents first century believers entering into musical worship vicariously, through the singing of another group or individual. Rather, the musical worship is participatory—the whole congregation corporately participates in worshipping God with one heart and voice" (116).
1 Corinthians 14:26 might pose a challenge to this argument, since Paul says of worship at Corinth: "Whenever you come together, each of you has a psalm…. Let all things be done for edification." If the "psalm" was a musical offering in worship (cf. Col 3:16), then this might be evidence of individual singing as part of the NT worship experience.
We might also point to choirs in OT worship. It seems that a group of Levites were tasked with special singing (not just leading the entire congregation in musical worship) [see 1 Chron 15:15-22; 16:4-6; 25:6-8; Neh 12:8]. The antiphonal refrain, "For his mercy endures forever," in Psalm 136 also seems to argue for a choir (cf. 2 Chron 5:13; 7:6).
We might also mention the various groups that sing in the heavenly worship recorded in Revelation (the four living creatures, the 24 elders, the angels, and all creatures).
Still, Deliberate Church’s point about the need for corporate musical worship is well taken, if not overstated. Musical worship should not be about a performance but the corporate service of God’s people. It should be God-centered and not man-centered. In fact, the authors point out that Capitol Hill BC uses a small group (choir?) of four people to lead congregational singing.