kind of christmas carols i sung as a child that i just adore. do them in my own way. i knew if i were to use children's voices it had to be the african children's choir. it has a connection to my campaigning work with hiv and aids and the things i've seen in africa. so i thought it would be very nice to give them a platform and for people to hear their voices and to find out a little bit more about them as well. >> while we have you here, can you do us a big favor and give us a little bit of a preview of what we're going to hear from you? >> oh, well, we're going to sing -- i'm going to sing -- ♪ angels from the realms of glory ♪ you know that one? ♪ wing your flight through i'm going to do that. i would have done god rest ye merry gentlemen, but i'm not going to do that. >> why not? >> they're asking me to sing. what else? >> why didn't you want to do "got rest you --"