Task: Question Answering
Input (English): Passage: We arrived at church in the morning . Today was my turn to play the piano for the service . In order to play I had a conversation with the lead singer on what songs he wanted to sing . Promptly at 9:00 the service started . The lead singer came to the front and welcomed everyone . He announced the first song . I had music for all the songs that we had picked out so I turned to the song he indicated . I then began to play and the congregation joined in with the song . We repeated this process for the next three songs . Once we were done I left the stage and went to my seat . Question: when did the congregation begin together? Option1: when piano started to play Option2: When the service ended.
Output (English): when piano started to play