Which band mate performed in most songs? Show me the last name.
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 firstname order by count(*) desc limit 1
Show the first name.
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