Lyrics:

Alice (spoken): How very curious!
MH&MH: A very merry unbirthday, to us, to us!
(unknown lyrics)
MAD: Oh, a very merry unbirthday;
MARCH: A very merry unbirthday;
MH&MH: A very merry unbirthday to us!
(instrumental by the teapots)
MARCH: A... very merry unbirthday--to me
MAD: To who?
MARCH: To me.
MAD: Oh, you!
MARCH: A very merry unbirthday--to you
MAD: Who, me?
MARCH: Yes, you!
MAD: Oh, me!
MARCH: Let's all congratulate us with another cup of tea.
A very merry un-a-birthday to ohhhhhh yooou!
MH&MH (spoken): No room, no room, no room, no room, no room, NO ROOM!
Alice (spoken): But I thought there was plenty of room...
MARCH (spoken): Ah, but it's very rude to sit down without being invited.
MAD (spoken): I'll say it's rude! It's very, very rude indeed! (lightly chuckles)
DORMOUSE (spoken): Very, very, very rude indeed! (snores)
Alice (spoken): Well, I'm very sorry... but I did enjoy your singing, and I wondered if you could tell me...
MARCH (spoken): You enjoyed OUR singing?
MAD: (spoken): Oh! What a delightful child! And uh...(inaudible)...get so excited... we never get compliments! You must have a cup of tea!
MARCH (spoken): Ah, yes, indeed... the tea... you must have a cup of tea!
Alice (spoken): That would be very nice. I'm sorry I interrupted your birthday party... uh, thank you.
MARCH (spoken): Birthday? Ha ha ha! My dear child... this is not a birthday party!
MAD (spoken): Of course not! (chuckles) This is an unbirthday party.
Alice (spoken): Unbirthday? Oh-I'm sorry, but I don't quite understand...
MARCH (spoken): It's very simple. Now--30 days have Sept-no... well... an unbirthday--if you have a birthday, then you...(laughs) She doesn't know what an unbirthday is!
MAD (spoken): How silly! Ho ho ho! Well... I-I... ahem... I shall ('illucidate?!')...