This is an important question:
I just learned (from Telly, on Sesame Street) that Twinkle, Twinkle, Baa Baa Black Sheep and The Alphabet Song all have the same tune.
Which one came first? Which ones stole the tune from the other? Who deserves the royalties?
WAG but they are all in the public domain.
I Don’t Know Whether To Kill Myself Or Go Bowling.
famous C&W song
Yours truly,
aha
WAG: The Alphabet Song (TAS), since you couldn’t write other lyrics until you learn the alphabet. 
BTW, I didn’t realize they were the same tune until my 4-year-old niece started singing parts of TTLS and TAS alternately with the same melody. (I was 35 at the time.)
Wrong thinking is punished, right thinking is just as swiftly rewarded. You’ll find it an effective combination.
And did you know that the Jeopardy Theme is the same as ‘I’m a Little Teapot’?
Spring Ice: 2 parts gin, 1 part Cointreau, 1 part Midori, 2 parts fresh squeezed lime, 7-up to fill - Garnish: Orange slice in bottom of glass.
By the way, the lyrics of “Twinkle, Twinkle, Little Star” are from a poem called “The Star” by Jane Taylor (born 1783, died 1824).
We’ve covered this issue in threads on the SDMB a couple times that I recall. I recommend looking up the discussion using the (ahem) search engine. I’d do it for you, but that thing and I don’t seem to communicate too well… 
One of the Bachs, btw, did a set of variations on the melody, quite delightful to play on the piano. 