There's a reason hit songs offer such guilty pleasure they're designed that way. Over the last two decades a new type of hit song has emerged, one that is almost inescapably catchy. Pop songs have always had a "hook," but today's songs bristle with them: a hook every seven seconds is the rule. Painstakingly crafted to tweak the brain's delight in melody, rhythm, and repetition, these songs are highly processed products. Like snack-food engineers, modern songwriters have discovered the musical "bliss point." And just like junk food, the bliss point leaves you wanting more

• Hook: The bliss point. You spin me round ; A continuity of hits
• First verse: Cheiron : Mr. Pop: and the Metalhead. Inside the box ; "The sign" ; Big Poppa ; Martin Sandberg's terrible secret ; Britney Spears : hit me baby ; "I want it that way"
• Chorus The money note : the ballad of Kelly and Clive. My ancestral hit parade ; The dragon's teeth ; The doldrums ; American Idol ; "Since u been gone"
• Second verse: Factory girls : cultural technology and the making of K-pop. "Gee"
• Chorus: Rihanna : track-and-hook. "Umbrella" ; "Ester Dean: On the hook" ; Stargate: those lanky Norwegian dudes ; "Rude boy"
• Bridge: Dr. Luke : teenage dream. Speed chess ; Katy Perry : altar call ; Melodic math ; Kesha : teenage nightmare
• Chorus: Spotify. The moment space
• Outro: Songworm. "Roar"