if you haven't watched the show, M'gann (Miss Martian) has a "mind link" thing, where she can mentally connect her team so they can talk without comms on missions. headcanon is that someone starts singing a song through the mind link while on a mission, its a song that the whole team knows so they all start singing it out-loud and the people their fighting are terrified because they're scarily in sync, Wally and M'gann are having a dance number, Dick and Kaldur are weirdly dramatic about singing, and Artemis can sing all the high parts perfectly
bonus: afterwards, M'gann asks what High School Musical is, Artemis, Wally, and Dick force the whole team to watch it ("team bonding" they say). M'gann loves it, she sings "We're all in this together" and "Get'cha head in the game" for *weeks*
bonus bonus: Dick and Conner act like they hate the movies, but secretly they actually love them and loves that M'gann loves them too