Back in 2008 Channel 7 was running a choir competition called, "Battle of the Choirs". If you search YouTube for "Battle of the Choirs" you should find lots of videos of the weekly competition.
The choir who won the competition was the University of Newcastle Chamber Choir which coincidently I used to sing in back when I was living in Newcastle studying at the Newcastle University Conservatorium.
Through some of my studio contacts, I was asked if I could record the piano/keyboard parts for the album of the winning choir to be co-released with the announcement of the winner of the competition. We recorded the album with PLW in South Melbourne as instruments only with the intent that the choir would record their parts later in Sydney.
It was an interesting experience as I think there were only 2 musicians playing in the studio at any one time because of different availability. It was pretty high pressure stuff with almost no time to record. You can see a snippet of footage of me recording "Playing to Win" with Phil as the engineer below in this YouTube video.