Many people won't sing along if they become frustrated while learning a song. Imagine that a song leader sings a long song in a foreign language, and then asks the children to repeat it back. They won't be able to do it. Their confidence will diminish and they won't want to sing. For this reason, use every tool you can to create confidence. Use word sheets or overhead projections. Use written music. If teaching by rote (see Teaching songs by rote, in Chapter 5), begin by speaking the words only and having the children repeat them. Then do the same with short phrases. Do all this in a way that makes the children feel good about themselves. Gradually, as their confidence and memory grow, they can learn the song. You may want to have them learn only the chorus or one verse the first time you introduce a song. Use some of the techniques mentioned above, like percussive singing, to make them sound better. Then say, "You are sounding good!"
Confidence, however, is not your final goal. You want to transcend confidence to create awe. Using the techniques described above, any group can sound wonderful. Creating awe simply means letting the group shine and letting the children become aware of their potential, their light. If the children are elated by how good they sound after you finish a song, then you have transcended confidence and entered the realm of wonder.