Bonhoga! I have an old book of Disney sheet music from the eighties (when I used to play the recorder at school, hehe!) and it has the music and lyrics to the birthday song!
It's called
Happy, Happy Birthday to You and was written in 1983 by Michael and Patricia Silversher. I couldn't find the lyrics online anywhere so I've copied them out for you.
I think they only use the chorus when they sing at DLRP and in the parades, but it's a funny song anyway so I thought you might like to know all of the words, hehe!
CHORUS
Happy birthday
It's Donald's birthday
Happy, happy birthday to you
Hey Donald!
Happy birthday
Happy birthday
Happy, happy birthday to you
He's funny, charming, our fine feathered friend
Today's his birthday; best wishes we send
He's full of surprises, quacks everyone up
He's crazy for Daisy; he's our Donald Duck!
(REPEAT CHORUS)
In ev'ry country he can be found
Throwing a tantrum and jumping around
The whole world loves Donald; today is his day
Across ev'ry nation you'll hear people say:
(REPEAT CHORUS)
Donald, we thank you for the joy that you bring
So have a great birthday now ev'ry one sing:
Happy birthday
Happy birthday
Happy, happy birthday to you
Which means happy birthday
Happy birthday
Happy, happy birthday to you
There's a party; a party today
A once a year occasion
A party is comin' his way
Donald's birthday celebration
Mickey and Minnie arrive with the cake
Daisy and Goofy bring Ludwig Von Drake
Huey, Dewey and Louie and Uncle Scrooge, too
They sing "Dear Donald, happy birthday to you"
Feliz cumpleanos!
(Spanish)
Bon anniversaire
(French)
O-tan joh-be o-meh-den-toh!
(Japanese)
(REPEAT CHORUS)
... goodness! It took a while to copy this out as it's been ages since I had to read sheet music and put things in the right place! I used to play this song a lot when I was little, hee! It surprised me, actually, when a few people had their birthdays during our June trip and I heard this song again.