>> it is something adele often turns to in her songs. mailman says it is not just that songs are happy or sad but they take us along for the ride. even pharrell's "happy." ♪ because i'm happy ♪ >> "happy." >> is authentic. >> full range of happy. >> happy and sad together. like salted caramel, he says. maybe that's why it feels so good. i'm david wright for "nightline" in new york. >> salted caramel. i like that. >> the candy -- you went right to the candy. forgot the whole piece was about. >> good morning, who wouldn't go for the sugar high. they say music has the power to heal. that soundwaves equal energy waves. that's why it moves you. >> that's why i have music on constantly around here. >> got your beats on. >> always. i need healing. >> announcer: this is abc's "world news now" informing