John Seabrook of the New Yorker shows how the Top 40 sausage is made.

Most of the songs played on Top Forty radio are collaborations between producers like Stargate and “top line” writers like Ester Dean. The producers compose the chord progressions, program the beats, and arrange the “synths,” or computer-made instrumental sounds; the top-liners come up with primary melodies, lyrics, and the all-important hooks, the ear-friendly musical phrases that lock you into the song. “It’s not enough to have one hook anymore,” Jay Brown, the president of Roc Nation, and Dean’s manager, told me recently. “You’ve got to have a hook in the intro, a hook in the pre-chorus, a hook in the chorus, and a hook in the bridge.” The reason, he explained, is that “people on average give a song seven seconds on the radio before they change the channel, and you got to hook them.”

It’s depressing to think that some music has become less art and more science.