here we go, we have phil ginsburg, the general manager of the san francisco recreation and parks departmentre going to help us out too. are we all ready to do this? all right. we're going to count down from ten as a group. here we go. ten, nine, eight, seven, six, five, four, three, two, one! [cheers and applause] [♪♪] >> say thank you. and now, we have a very special added performance for every class. you may have seen them on "america's got talent" or maybe on their recent jc penney commercial. they're here now to please welcome san francisco's first family of song, the curtis family c-notes. [cheers and applause] >> hi. how are ya'll doing, san francisco? this is the most beautiful tree i have ever seen and it's so good to be out here with all ya'll. give yourself a round of applause. [applause] and i think i hear the mayor. yes. all right. guys, you ready? [cheers and applause] we've got nile on bass. papa on keys. kiki. zahara, phoenix. and i'm momma c. we need the mic por favor sound people. so we've got a little technical difficulties. no worries. what we can do, let's give it up for