Continuing the alienated-young-man theme that seemed to preoccupy Paul Simon in his early songwriting career, "I Am a Rock" also follows the successful acoustic-electric, pop-folk formula that Simon & Garfunkel happened upon almost accidentally with their 1964 breakthrough hit single "Sound of Silence." The latter song was originally recorded with only acoustic guitar accompanying the duo's pristine harmonies. It was turned into an electrified pop recording without the pair's knowledge by producer Tom Wilson -- who was having success with similar arrangements for Bob Dylan -- on order of Columbia Records. When "Sound of Silence" resulted in a number one record, Simon & Garfunkel recorded a number of other songs with electric bass, guitar, organ, and drums to round out the album Sound of Silence (1966), capitalizing on the success of the title track. Like "I Am a Rock" from the album, the sound was usually closer to the jangly West Coast folk sound of the Byrds and the Mamas and the Papas than to Dylan's often raucous and hard-driving blues treatments. Simon & Garfunkel's sweet harmonies always take off a bit of edge, even when turning it up a notch with harder, Louvin Brothers-via-the Everly Brothers singing. "I Am a Rock" was also a hit for the duo.
As with "Sound of Silence," "I Am a Rock" starts softly, with a lilting, triplet folk-guitar lick and Simon's gentle, almost whispered voice setting the scene: "A winter's day/In a deep and dark December," the band kicking in for, "I am alone/Gazing from my window to the streets below/On a freshly fallen silent shroud of snow/I am a rock/I am an island." His lyrics tread the same introspective teenage/young adult ground as Brian Wilson's 1963 classic "In My Room," though Simon has not quite yet developed the subtlety demonstrated by Wilson and his co-writer, Gary Usher. But Simon does strive for greater depth: "I've built walls/A fortress deep and mighty/That none may penetrate/I have no need of friendship/Friendship causes pain." His lyrics sound a bit labored and self-conscious as he finishes the verse with the plodding, "It's laughter and it's loving I disdain." What Simon does exhibit, however, is a well-developed sense of irony: With the final verse, he seems to be either deflating his sense of self-important misanthropy or poking fun at a distrustful, emotionally frustrated narrator, as if it was not Paul Simon singing the song confessionally after all, but a singer giving voice to a character: "I have my books/And my poetry to protect me/I am shielded in my armor/Hiding in my room, safe within my womb/I touch no one and no one touches me/I am a rock/I am an island," capping it with the sad-sack lament, again singing in a quiet voice, "And a rock feels no pain/And an island never cries." The narrator, after trying to disprove John Donne's Meditation 17, "No man is an island," finally succumbs and seems to ultimately agree. And the reprised folk-guitar riff finishes the frame.