The staff at Seattle Grace hospital will show off their talents in a one-off special as part of the series' current seventh season, but Walsh admits preparing for the role was no easy task.
And she had so much difficulty during her first singing lesson, show bosses even offered to leave her character Dr. Addison Montgomery out of the musical scenes.
In an interview with U.S. breakfast show Good Morning America on Thursday (03Feb11), she says, "I had to take lessons and it was a traumatic experience for me, tears were shed. I went in for lessons and... put it this way, after the first lesson with the vocal coach and the musical director was there, he came up to me and was like, 'You know, you don't have to do this'. I was like, 'No, wait! I really (want to).'"
The episode is due to air in the U.S. later this month (Feb11).