CREATE TABLE table_73924 ("Episode" TEXT, "Theme" TEXT, "Song choice" TEXT, "Original artist" TEXT, "Order #" TEXT, "Result" TEXT)

Who is the original artist of the song choice ' The Letter '?
SELECT "Original artist" FROM table_73924 WHERE "Song choice" = ' The Letter '
SELECT "Original artist" FROM "table_73924" WHERE "Song choice" = ' The Letter '