The song’s source material could not have been more unlikely: A local TV news report from Huntsville, Ala., about an intruder who climbed into a woman’s bed and tried to assault her.

But with some clever editing and the use of software that can turn speech into singing, the Gregory Brothers, a quartet of musicians living in Brooklyn, transformed an animated and angry rant by the victim’s brother into something genuinely catchy.

The resulting track, “Bed Intruder Song,” has sold more than 91,000 copies on iTunes, and last week it was at No. 39 on the iTunes singles chart. Its video has been viewed more than 16 million times on YouTube.

And to top it off, the song was No. 89 on Billboard’s Hot 100 chart for the week of Aug. 20, ranked among singles by Katy Perry and Usher. The chart takes into account sales and radio play as well as online streaming.

“It’s not easy to get on that chart,” said Silvio Pietroluongo, director of charts at Billboard. “There are plenty of decent radio songs that don’t reach the sales chart.”

Russ Crupnick, an analyst at NPD, said the song’s success pointed to a shift in how music is shared and discovered. Around 70 million Americans buy a CD each year, he said, which is on par with the number of people who are now listening to and finding new music on YouTube.

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