Find all the songs that do not have a back vocal.
CREATE TABLE vocals (
    songid VARCHAR
)

CREATE TABLE songs (
    title VARCHAR,
    songid VARCHAR
)
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"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Find all the songs that do not have a back vocal. ### Input: CREATE TABLE vocals (
    songid VARCHAR
)

CREATE TABLE songs (
    title VARCHAR,
    songid VARCHAR
) ### Response: 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"