i agree whole heartily with YANG.... LISTEN FOR THE SONG (first to melody notes of the associated tune) IN THE INTERVAL...BUT ALSO GET USED TO HOW IT MAKES U FEEL.... ITS SORTA LIKE HEARING CHORDS...ESPECIALLY YOUR 7ths...m7, M7, dom 7, dim7, m7flat5 , they ALL HAVE a DIFFERENT QUALITY....AND ONCE U...

sometimes i have some difficulty...with 4ths and 5ths.... but not much anymore.. perfect 4th up .....HERE COMES THE BRIDE... Perfect 5th up twinkle twinkle little star,, or Georgia Girl when they are descending ...work on flipping them in your head... sing the 2nd time first and the first tone secon...