Why pop songs last about three minutes
The three-minute pop song was shaped by a spinning disc. Early records turned at 78 revolutions per minute, and a ten-inch disc held only about three minutes of music on each side. From 1949 the seven-inch SINGLE, playing at 45, fitted a song of similar length comfortably, and radio stations liked short songs so they could play more of them. Songwriters learned to fit a whole story — verse, CHORUS, verse, CHORUS, a bridge and one last CHORUS — into roughly three minutes, and the habit stuck long after the technology moved on.
Streaming has squeezed songs again. A play only counts as a stream once someone has listened for 30 seconds, so many modern hits skip the long introduction and get to the HOOK quickly, before anyone has time to press skip.
An oil engineer fixed the singing
AUTOTUNE was invented by Andy Hildebrand, an engineer who had spent years using sound waves to search for oil deep underground. At a dinner party, a guest joked that he should invent a box that would make her sing in tune. He realised the same maths could spot a VOCAL drifting off the right note and nudge it back. It went on sale in 1997, designed so that listeners would never notice it.
A year later the producers of Cher's song 'Believe' turned the setting right up, so that her voice flipped between notes with a robotic warble. The song went to number one around the world, and a tool built to hide mistakes became one of the most recognisable sounds in pop.
What makes an earworm
Scientists call it involuntary musical imagery, and almost everyone gets it. In 2016 researchers at Durham University asked around 3,000 people which songs got stuck in their heads, then looked for patterns. The most common EARWORM songs were fairly fast, had a simple tune that rose and fell in a familiar shape, and included a surprising jump or a repeated note that made them stand out. Top of the list was Lady Gaga's 'Bad Romance'. Other studies suggest two cures: chewing gum, or listening to the song all the way to the end.
Songwriters aim for that effect on purpose, and the part built to lodge in your head is called the HOOK. BUBBLEGUM pop, a late-1960s name for sweet, simple songs aimed at young teenagers, was made almost entirely of hooks. Its biggest hit, 'Sugar, Sugar', was the top-selling single of 1969 in America, and it was credited to the Archies, a band that existed only as cartoon characters.
The hitmakers you've never heard of
Many of the biggest songs are written by people most listeners couldn't name. The Swedish songwriter Max Martin has co-written hits for Britney Spears, Katy Perry, Taylor Swift and The Weeknd, and only Paul McCartney has written more songs that reached number one on the American CHART. Writing pop is often a team job, with one person building the beat, another shaping the MELODY and another polishing the words, sometimes all in a single day in the STUDIO. The goal never changes: a line simple enough for a whole stadium to sing back. For the singers themselves, see our pop stars puzzle.