Instrumentation includes guitar strings, piano lines and vocals. Written in the key of Ab major, the beat is set in common time and moves at a moderate 84 beats per minute. It also incorporates a Queen-referencing chorus: "I want you to rock me, yeah, I want you to hit the pedal, heavy metal, show me you care." The track's lyricism regards a nostalgic message about a former significant other and a blatant double entendre for sexual intercourse. In the regard to its double entendre, Grigg noted, "but at the same time, there's a vulnerability in it that's, like, so sweet for girls. It's a little self-deprecating. There's not a lot of overt machismo in the song". "I approached it like high school," said Hollander: "On the first record, they were freshmen, innocent and wide-eyed. Now it's sophomore year, there are parties and driver’s licenses, and the world is theirs for the taking. That's what I wanted to capture". The song garnered mostly positive reviews from critics, who centred on production quality and its rock elements. "The New Zealand Herald" writer Lydia Jenkin deemed "Rock Me" one of "the most banal songs ever written", but noted that the group "know what teenage girls want to hear." Idolator critic Sam Lansky praised the track as "irresistible" and commended its sonic palette as "explosively punchy". Writing for HitFix, Melinda Newman favoured its "nearly hypnotic anthemic" beat, and noted that "Rock Me" seems perfectly tailored to become a live staple. Ben Rayner of the "Toronto Star" thought the song's Queen-references are "clever", assessing: "to show that One Direction’s puppeteers aren't totally operating on autopilot." Robert Copsey from Digital Spy opined that the song's "simple-yet-genius catchiness" is its strongest attribute. "Billboard" reviewer Chris Payne applauded its rock elements, regarding it as "welcome" deviation from "Take Me Home" predominant bubblegum pop sound. In contrast to the positive reception, Alexis Petridis, writing for "The Guardian", criticised the song as "excruciating", describing its lyricism as tedious and uninspiring. In the week of 18 November 2012, "Rock Me" debuted at number one on the US Bubbling Under Hot 100 Singles chart due to strong digital download sales.