Meghan Trainor, kicking off the Citi Summer Concert Series in front of a cheering audience that packed the TODAY plaza. Crowned by a lovely pastel pink head of hair, Trainor got everybody grooving with songs like her 2014 hit “All About That Bass,” plus “No Excuses,” “Let You Be Right” and “Like I’m Gonna Lose You.” Trainor has been keeping busy lately: Not only has she been working on her third album, she’s also been appearing on Fox’s singing competition “The Four” as a judge. Visiting TODAY, she pointed out her fiancé, “Spy Kids” actor Daryl Sabara on the plaza, noting, “I’m so in love.” While they haven’t set a date for the wedding, she added, “I’m locking it down.”