Deke Sharon laughs at the idea that the current a cappella boom could somehow have been planned.
"Look at this from the perspective of someone in the music industry," says Sharon, who not only produced the a cappella contest The Sing-Off but was vocal producer on the movie Pitch Perfect and its upcoming sequel. "They're thinking they need to get this current pop song and thinking about singles from albums and what songs from the movie are really going to hit."
Instead, it was Cups, Anna Kendrick's song from Pitch Perfect, that became a massive pop hit that busted down the doors to the mainstream for this new wave of a cappella music.
"The idea that a solo, lone a cappella performance, with the sound of a little cup banging in the background, of a folkie 1934 bluegrass song, would become the biggest song from a music movie in the past five years, until Let It Go, is preposterous," Sharon says.
"Find me something that's more ridiculous than that song becoming quadruple platinum … It was the culmination of all of the fun, the good vibes that went into the movie."
Those good vibes are expected to multiply now, as a cappella gets ready to move to the next level. Pitch Perfect 2 is set to open in theatres in May, with a huge marketing push behind it that included an ad during the Super Bowl. The Sing-Off concert tour is playing to packed venues across the US. And Pentatonix, the a cappella phenomenon that had 2014's fourth-biggest album with That's Christmas to Me, won their first Grammy this month.