user: Question: Who is the original artist of the song choice " The Letter "?
Columns: ['Episode', 'Theme', 'Song choice', 'Original artist', 'Order #', 'Result']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Audition', "Auditioner's Choice", '" Ain\'t No Sunshine "', 'Bill Withers', 'N/A', 'Advanced']
SQL:

assistant: SELECT "Original artist" FROM "Table" WHERE "Song choice" = '" The Letter "';