The band wrote this song with Sam Hollander, who was also working with Panic! at the Disco (Emperor's New Clothes
) and Pentatonix ("Sing
") around this time. Hollander was a huge Fitz and the Tantrums fan and had been trying to get in with them for a while. He finally got his chance when the band got off to a slow start on the album and brought him in for a fresh perspective. It was a good call: Hollander clicked with them right away.
"'HandClap' was an idea that came running and screaming to me," Hollander told Songfacts
. "I sang that couplet, 'I can make your hands clap,' and he did this crazy five-clap thing, and right then and there I thought we had something magical.
But there was no particular plan of attack with it. I don't think we were trying to write a hit, per se, because the song is so strange. The first verse repeats twice and it's just this strange cacophony of chaos. The fact that it worked was amazing."