An apparently impromptu dance routine added to the fun at this year’s end-of-semester picnic.

Dozens of students, faculty and staff were in on the surprise, inspired by YouTube videos of seemingly random outbreaks of choreography in public places. The group was able to keep its plans secret until the dancers took to the Campus Center lawn to the Beatles number “Twist and Shout.”

The performance just added to the fun at the campus celebration. An annual tradition, this year’s event included a picnic, inflatable games, musical entertainment and a henna tattoo artist.