CREATE TABLE band (id NUMBER, firstname CLOB, lastname CLOB)
CREATE TABLE performance (songid NUMBER, bandmate NUMBER, stageposition CLOB)
CREATE TABLE vocals (songid NUMBER, bandmate NUMBER, type CLOB)
CREATE TABLE songs (songid NUMBER, title CLOB)
CREATE TABLE instruments (songid NUMBER, bandmateid NUMBER, instrument CLOB)
CREATE TABLE albums (aid NUMBER, title CLOB, year NUMBER, label CLOB, type CLOB)
CREATE TABLE tracklists (albumid NUMBER, position NUMBER, songid NUMBER)

What is the last name of the musician that have produced the most number of songs?
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
SELECT "T2"."lastname" FROM "performance" "T1" JOIN "band" "T2" ON "T1"."bandmate" = "T2"."id" JOIN "songs" "T3" ON "T1"."songid" = "T3"."songid" GROUP BY "lastname" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY