How many songs have vocals of type lead?
SELECT count(DISTINCT title) FROM vocals AS T1 JOIN songs AS T2 ON T1.songid  =  T2.songid WHERE TYPE  =  "lead"
SELECT count(DISTINCT title) FROM vocals AS T1 JOIN songs AS T2 ON T1.songid  =  T2.songid WHERE TYPE  =  "lead"
[{'count(DISTINCT title)': 0}]