CREATE TABLE Songs (SongId VARCHAR(255)); CREATE TABLE Band (lastname VARCHAR(255), id VARCHAR(255)); CREATE TABLE Performance (bandmate VARCHAR(255), SongId VARCHAR(255))
What is the last name of the musician that have produced the most number of songs?
    
SQL: SELECT T2.lastname FROM Performance AS T1 JOIN Band AS T2 ON T1.bandmate = T2.id JOIN Songs AS T3 ON T3.SongId = T1.SongId GROUP BY lastname ORDER BY COUNT(*) DESC LIMIT 1