user: Question: Who is the original performer when the episode is Casting?
Columns: ['Episode', 'Theme / Date', 'Song title', 'Original performer', 'Result (Placement)']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Casting', 'Free choice', '" Tell Me \'bout It "', 'Joss Stone', 'to Bootcamp']
SQL:

assistant: SELECT "Original performer" FROM "Table" WHERE "Episode" = 'Casting';