Intro:

        Tra la-la-la-la la-la-la-la
        Happy birthday sweet sixteen
        Tra la-la-la-la la-la-la-la
        Happy birthday sweet sixteen

Verse 1:

         Db                 F7
        Tonight's the night    I've waited for
        Bbm                       Db7
        Because you're not a baby     anymore
        Gb             Gdim              Db/Ab          Bb7
        You've turned into the prettiest girl I've ever seen
         Eb7                     Ab7
        Happy birthday sweet sixteen

Verse 2:

        What happened to that funny face
        My little tomboy now wears satins and lace
        I can't believe my eyes you're just a teenage dream
         Eb7   Ab7               Db
        Happy birthday sweet sixteen

Bridge:

        Ab7
        When you were only six
        Db
        I was your big brother
        Ab7
        Then when you were ten
        Db
        We didn't like each other
        Bb7
        When you were thirteen
                    Ebm
        You were my funny valentine
             Eb7 [N.C.]
        But since you've grown up
              Eb7 [N.C.]
        Your future is sewn up
         Ab7
        From now on you're gonna be mine, so

Verse 3:

        If I should smile with sweet surprise
        It's just that you've grown up before my very eyes
        You've turned into the prettiest girl I've ever seen
         Eb7   Ab7               Db    A7
        Happy birthday sweet sixteen

[key change]

[repeat verse 3, in D]

        D                 F#7
        If I should smile     with sweet surprise
        Bm                                D7
        It's just that you've grown up before my very eyes
         G             G#dim             D/A             B7
        You've turned into the prettiest girl I've ever seen
         E7    A7                D
        Happy birthday sweet sixteen

Coda [repeat to fade]:

         D              Bm
        Tra la-la-la-la la-la-la-la
                G             A
        Happy birthday sweet sixteen