What is the first name of the musician that have produced the least 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(*) asc limit 1
How about the musician who 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