Table schema:
CREATE TABLE Songs (SongId VARCHAR); CREATE TABLE Band (firstname VARCHAR, id VARCHAR); CREATE TABLE Performance (bandmate VARCHAR)

Question: Find the first name of the band mate that has performed in most songs.
SQL: SELECT t2.firstname FROM Performance AS t1 JOIN Band AS t2 ON t1.bandmate = t2.id JOIN Songs AS T3 ON T3.SongId = T1.SongId GROUP BY firstname ORDER BY COUNT(*) DESC LIMIT 1