Carmelo Anthony -- When It Comes To Team Singalongs ... Count Me Out

Carmelo Anthony is a lot of things -- 9 time NBA All Star, former NBA scoring champ and he won an NCAA title -- but when it comes to belting out Vanessa Carlton, he just isn't a fan.

Melo was caught on video by his US Olympic Basketball teammate DeMar DeRozan looking awfully salty while DD, Kyrie Irving and Jimmy Butler sang their hearts out.

We're not sure if he was just tired or flat out hates "A Thousand Miles" (if that's possible?) ... but that scowl is one for the ages.

Take it away, Terry ...