Background: Florence Leontine Mary Welch was born in Camberwell, London on 28 August 1986. Her father is Nick Russell Welch, an advertising executive. Her mother, Evelyn Welch (nee Evelyn Kathleen Samuels), is an American emigrant from New York City who was educated at Harvard University and the Warburg Institute, University of London. Evelyn is currently Professor of Renaissance Studies and Vice-Principal for Arts and Sciences at King's College London.
Context: According to Welch, the band name "Florence + the Machine" had "started off as a private joke that got out of hand. I made music with my friend, who we called Isabella Machine, to which I was Florence Robot. When I was about an hour away from my first gig, I still didn't have a name, so I thought 'Okay, I'll be Florence Robot/Isa Machine', before realising that name was so long it'd drive me mad". In 2006, Welch's performances with Isabella Summers in small London venues under the joint name Florence Robot/Isa Machine began to attract notice. In 2007, Welch recorded with a band named Ashok, who released an album titled Plans on the Filthy Lucre/About Records label. This album included the earliest version of her later hit "Kiss with a Fist", which at this point was titled "Happy Slap".  Florence and the Machine released their debut album Lungs in the United Kingdom on 6 July 2009. The album was officially launched with a set at the Rivoli Ballroom in Brockley, South East London. It peaked at number one in the UK and number two in Ireland. As of 6 August 2009, the album had sold over 100,000 copies in the UK and by 10 August it had been at number two for five consecutive weeks. Following its 25 July 2009 release for download in the United States, the album debuted at number seventeen on the Billboard Heatseekers Albums chart, ultimately peaking at number one. The album was released physically in the US on 20 October by Universal Republic. The album was produced by James Ford, Paul Epworth, Steve Mackey and Charlie Hugall.  Welch contributed vocals to David Byrne and Fatboy Slim's 2010 album Here Lies Love, an album about Imelda Marcos. As of January 2011, Welch was working with Drake on material slated for his upcoming album.  On 27 February 2011, Welch replaced pregnant Dido and sang her portion of Best Original Song nominee "If I Rise" (from 127 Hours) with A. R. Rahman at the 83rd Academy Awards.
Question: What was the joke

Answer:
I made music with my friend, who we called Isabella Machine, to which I was Florence Robot.