Tab by: Chase Chafin
http://www.reverbnation.com/chasechafinandtheconductor
Don't kill me if I'm wrong, but there's no other chords for this song, and it sounds right.

Basically, it stays with the same chord progression the whole song.

Intro: A (stay on A until song takes off)
A E7 D D7 A E7 A X2

Verse 1:
   A                E7          D               D7
I know that you've heard this old song sung before,
         A                             E7             A
but you ain't heard it while you was walking out the door
     A        E7         D              D7
It's goodbye baby, honey your time has come,
  A                     E7                  A
Turn the tables and now you the one on the bum

Chorus:
     A     E7       D        D7
It's La La La, singing La La La
     A                 E7          A
I'm so happy, got me singing La La La

Harmonica Solo:
A E7 D D7 A E7 A X2