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

What is the type of vocals that the band member with the last name 'Heilo' played 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
SELECT "type" FROM "vocals" "T1" JOIN "band" "T2" ON "T1"."bandmate" = "T2"."id" WHERE "Heilo" = "lastname" GROUP BY "type" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY