Show me all vocal types played by the band mate with last name "Heilo".
select type from vocals as t1 join band as t2 on t1.bandmate = t2.id where lastname = "Heilo" group by type
Which one did they play the most?
select type from vocals as t1 join band as t2 on t1.bandmate = t2.id where lastname = "Heilo" group by type order by count(*) desc limit 1