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
CREATE TABLE vocals (bandmate VARCHAR); CREATE TABLE band (id VARCHAR)
นักร้องประเภทไหนที่เพื่อนร่วมวงนามสกุล 'ไฮโล' เล่นบ่อยที่สุด?
Which vocal type has the band mate with last name "Heilo" played the most?