The "what is wrong" argument is opposed to the regulative principle of worship. Even if it can be proven to be "not-wrong", it is forbidden if not commanded. But the Scripture is expressly against it. "Let the prophets speak two or three, and let the other judge. If any thing be revealed to another that sitteth by, let the first hold his peace." Let's deal honestly with the Scripture. It speaks expressly to the question of receiving individual compositions into the service. The compositions are to be delivered by the individuals themselves, and the rest of the congregation are to sit silently and judge what is spoken. Clearly, then, praying and preaching do not serve as a scriptural parallel for congregational singing.