Like most of his peers in hip-hop, Jay-Z heavily samples a vast back catalogue of pop music for beats, melodies, and material that he can approbate for his songs. "Empire State of Mind," like much of The Blueprint 3, is built off of samples.
"Empire State of Mind" has two key samples. The beat is taken from the intro of Isaac Hayes' "Breakthrough." Meanwhile, the piano loop is taken from the intro of The Moments' "Love on a Two-Way Street." Each of these has been sped up (so the key is one half-step higher too; instead of being in the key of F major—as in The Moments' song—the song is in F# major) and, of course, taken out of context. You'd probably not recognize that these are samples without being told so. If you don't happen to be a huge fan of The Moments or Isaac Hayes, you probably won't even realize that two of the three core aspects of a song—the melody, the harmony (chords), and the rhythm—aren't original at all. And since Alicia Keys, who actually plays the "Love on a Two Way Street" piano line in live performances of the song, is the featured artist on the track, the idea of sampling is even further obscured. This leads us to an important understanding of the art of sampling.
Sampling can occur as a shout-out to another artist, as something that listeners will recognize and latch on to—as when Eminem sampled the well-known Aerosmith song "Dream On" in his 2002 song "Sing for the Moment" – but more often samples are taken from obscure sources. The idea is to take a small portion of the song, speed it up, slow it down, loop it, whatever, and incorporate it with new sounds, making it fresh and new. Whoever heard of The 4 Levels of Existence? Probably not you. And yet, a sped up version of the intro to their song "Someday in Athens" provides the heart of "Run This Town," the other mega-hit from The Blueprint 3.
Something similar is true for "Empire State of Mind." You've probably heard of Isaac Hayes, especially if you watch South Park, and maybe you've even heard of The Moments, but neither of these songs is likely to be familiar to you. Actually, they're both not even especially great songs. After the fabulous (but too slow) intro, "Love On A Two-Way Street" transforms into a pretty uninteresting ballad. Isaac Hayes' "Breakthrough" is a more-or-less throwaway funk song. Part of the game in producing hip-hop is finding hidden gems like this. Like rap itself, sampling relies so much on memory. It's usually not interesting if a song samples something well-known, so getting these deep cuts gives producers a lot of cred.
While Jay-Z's rap is more interesting lyrically than musically, there is still Alicia Keys' vocal track to think about (since she actually sings!). Her vocals on the chorus have been praised as the emotive heart of this song by some critics; one declared that Keys' undeniably catchy melody will "annoy its way into ubiquity." That's mostly true. The only thing that's wrong with that statement is actually the tense. The melody already has annoyed its way into ubiquity! Remember Coldplay's The Scientist? The vocal hook is practically identical to Keys' melody during the lines "These streets will make you feel brand new / Big lights will inspire you" and "Concrete jungle where dreams are made of / There's nothin' you can't do." Might we say that Alicia Keys is "sampling" her melody here?
Maybe. It's not unfair to think of each core aspect of the song, then – the melody, the harmony, and the rhythm – as being somewhat unoriginal, or at least appropriated from earlier sources. In fact, thinking about rap as an art form of memory that necessarily alludes to other rappers and singers (as when Jay-Z quotes Sinatra's "If I can make it there / I'll make it anywhere" and Young Jeezy's song "24 & 23"), the source of most of the song's material isn't really the singer or the producer. It's the past.
This is by no means necessarily a bad thing, however. The whole idea of "pop music" is that the music is "popular." How can something be "popular" if it is entirely unfamiliar? Most every piece of pop music copies something else. What makes a piece of music interesting is not really its authorship so much as the recombination of these unoriginal elements into something fresh and new (even if never wholly original). "Empire State of Mind" is a collage of sounds in this way, and appropriately so. Because New York is the city that it is, with eight million stories to be told, how can Jay-Z even attempt a definitive New York anthem without reinventing and recontextualizing the stories, lyrics, and music of others?