CREATE TABLE table_11951237_2 (musical_guest_and_song VARCHAR2, production_code VARCHAR2)

How many musical guests and songs were in episodes with a production code k0519?
SELECT COUNT(musical_guest_and_song) FROM table_11951237_2 WHERE production_code = "K0519"
SELECT COUNT("musical_guest_and_song") FROM "table_11951237_2" WHERE "K0519" = "production_code"