The Rainbow Chamber Singers present classical music in a light and fun way, which has made them an online sensation.[Photo/China Daily]

A Chinese musician's effort is driving chorus singing online and in the real world.

The year began on an interesting note for conductor and composer Jin Chengzhi.

On Jan 9, he led the Rainbow Chamber Singers, a Shanghai-based amateur choir, to a show in their city. At the end of a regular performance, the choir's 40 members put on their sunglasses and sang a song, titled Where On Earth Did You Leave the Key to My Apartment, Zhang Shichao?

Written by Jin, the song is about Zhang Shichao, his former classmate from the Shanghai Conservatory of Music, who forgot to leave their room key behind before going on a date.

With simple lyrics stating Jin's frustration and anger over not being able to get in touch with Zhang despite repeated phone calls, the song is divided into sections that include a combination of chorus with elements from Sancta Maria, a soprano aria based on the opera, Rustic Chivalry, and one of Taiwan pop singer Jay Chou's hits, Cowboy on the Run.