query: SELECT DISTINCT title FROM vocals AS t1 JOIN songs AS t2 ON t1.songid  =  t2.songid EXCEPT SELECT t2.title FROM vocals AS t1 JOIN songs AS t2 ON t1.songid  =  t2.songid WHERE TYPE  =  "back"
question: What-all the names of the songs do ain't back no vocals?
query_toks: SELECT DISTINCT title FROM vocals AS t1 JOIN songs AS t2 ON t1.songid = t2.songid EXCEPT SELECT t2.title FROM vocals AS t1 JOIN songs AS t2 ON t1.songid = t2.songid WHERE TYPE = `` back ''
query_toks_no_value: select distinct title from vocals as t1 join songs as t2 on t1 . songid = t2 . songid except select t2 . title from vocals as t1 join songs as t2 on t1 . songid = t2 . songid where type = value
question_toks: What-all the names of the songs do ain't back no vocals?