Task: Text to Code
Input (English): SQL: SELECT T2.Firstname , T2.Lastname FROM Songs AS T1 JOIN Band AS T2 JOIN Instruments AS T3 ON T1.SongId = T3.SongId AND T3.BandmateId = T2.Id WHERE T1.Title = "Der Kapitan"
Feedback: Make sure that artist performed back stage .
Output (English): SELECT T2.firstname ,  T2.lastname FROM Performance AS T1 JOIN Band AS T2 ON T1.bandmate  =  T2.id JOIN Songs AS T3 ON T3.SongId  =  T1.SongId WHERE T3.Title  =  "Der Kapitan" AND T1.StagePosition  =  "back"