Karmin's new single starts with singer Amy Heidemann singing. She doesn't break into her signature speedy raps until the end of the first verse. Her vocals are so strong that you miss them when she spits her rhymes -- even though her spitting is what made the group famous.

Despite the title, the song isn't sad. It's an ode to a new crush: "I've been waiting all day / For you to call me, baby / So let's get up, let's get on it / Don't you leave me brokenhearted tonight." The lyrics are relatable to anyone who's been subject to the three-day rule.

While the song is catchy as can be, it falls victim to the group's own contrivances. When Heidemann refers to mullets in her raps and insists on inserting "Cheerio!" into each verse, it's polarizing to listeners: You either like their schtick or you don't. If you do, it's creative and quirky and cute. If you don't, it gets annoying quickly and can easily be perceived as the talented duo trying way harder than they need to.

When Heidemann is singing instead of rapping, the tune actually evokes Whitney Houston's 'I Want to Dance With Somebody' more than the Kreayshawns and Chris Browns -- to whom Karmin has been compared. The Dr. Luke-inspired beat is pure radio gold, and when combined with Heidemann's soaring choruses, should shoot this song straight into the Top 40. Once Heidemann and partner in crime Nick Noonan find their confidence, they'll be unstoppable -- especially if they perform this on 'Saturday Night Live.'