Canadian singer Carly Rae Jepsen has kept her year-long romance under wraps, but the "Call Me Maybe" singer, 26, has been dating musician Matthew Koma, according to

Koma is featured on the electronic dance tune, "Spectrum" by Zedd, but his primary focus is rock music.

A party guest spotted him and Jepsen holding hands a party guest at the GetGlue HD Launch Party at the Standard, East Village in New York City.

A source told People, "He introduced her as his girlfriend. He seemed really excited about it, and she was smiling from ear to ear by his side during the introduction. He seems like a really nice and personable guy."

Jepsen's "Call Me Maybe" landed the longest number-one run on the pop charts so this year.