Dan Martin from NME reviewed the album and said the following of the song: "Starting off synthy, slinky and just a little bit funky, 'Sing' then erupts into another euphoric call to mass doing-stuff-together as waves of filthy bass cascade around Gerard as he sings, "You've got to be what tomorrow needs" as he dodges elephant-stomp drums.

"[6] Trash Hits said of the song: "This is a slower, smouldering effort which jangles in a Depeche Mode style while Gerard Way murmurs his way through.

During this time, Korse (Grant Morrison) is activated by BL/ind headquarters' head of security and accompanied by reinforcement draculoids and guards to stop the Killjoys.

This causes Party Poison to hesitate in the fight and be grabbed by Korse who grasps him by the neck and tragically shoots him beneath his chin.

Shortly after Party Poison's death, Kobra Kid (Mikey Way) manages to wound Korse in the knee before getting shot himself by the draculoids and is killed.

[citation needed] This song was performed on the TV series Glee in the second-season episode "Comeback", which was released as a single on iTunes in February 2011.