– alongside Harrison. Featured artist Jay-Z became involved late in the song's production. Around 3 am, he came to the studio and recorded a rap verse, which he improvised in about ten minutes. The recording of "Crazy in Love" took place nearly three months following the meeting of Beyoncé with Harrison. Music and lyrics According to the sheet music published at Musicnotes.com by Alfred Music Publishing, "Crazy in Love" was composed in the key of D-minor and F-major. It incorporates influences of 1970s-style funk, hip hop, and soul. As commented by Robert Webb of The Independent, the old soul influences in the song seem to have been derived from the horn hook, which samples the 1970 song "Are You My Woman? (Tell Me So)." Having a go-go vibe, "Crazy in Love" is built on a hip hop beat. Beyoncé told The Sunday Herald that the beat is "so hard that it makes your heart hurt." The song's tempo is a moderate 100 beats per minute, in common time. Beyoncé's vocal range spans around one and a half octaves in the song, from the low note of A3 to the high note of F5. "Crazy in Love" uses two major chords, B♭ and G, a minor third apart. One of the main vocal riffs uses the traditional cowbell rhythm often found in samba music. Lisa Verrico of The Times magazine, wrote that "Crazy in Love" makes use of big drums and bits of brass. According to Natalie Nichols of the Los Angeles Times, the lyrics of "Crazy in Love" reference a state of romantic obsession. Beyoncé said that the song talks "about how, when you are falling in love, you do things that are out of character and you do not really care because you are just open." Anthony DeCurtis of Rolling Stone wrote that "Crazy in Love" has "such a cauldron of energy," that Beyoncé sounds "loose and sexy," gripped by emotions she "can neither understand nor control." The lyrics are composed in the traditional verse-chorus form. Jay Z opens the song with a brief spoken verse-rap, containing the lyrics: "Yes! So crazy right now. Most incredibly, it's your girl, B. It's your boy, Young. You ready?" After Beyoncé delivers the "uh-oh, uh-oh" catchphrase, Jay Z continues the monologue. Beyoncé begins the first verse, followed with the whistle-backed chorus. She repeats the "uh-oh, uh-oh" phrase, leading to the second verse.