(CNN) John Legend took the stage at a rally for Democratic vice presidential nominee Sen. Legend's wife, Chrissy Teigen, and their young children appeared on stage together briefly. "I want to send a shoutout -- actually, can you come onstage, baby?" My son, Miles, is here. "I want to do a special song that I dedicated to my wife a little while ago," he said." I wrote this song as a tribute to our relationship and the fact that love can get us through all kinds of tough times.