Carousel of Progress Concluding Song

The final song segment has the same title, "There's a Great Big Beautiful Tomorrow," but who're the artists?

I'd post the YouTube link itself, but I'm too new on here to be able to.
If you can, specifically search "Part 2 Disney's Carousel of Progress" into YouTube and click into the first result. You can hear the song part I'm asking about from 09:21-end.

If you know where I can get the song file/the artists, please post your answer. Greatly appreciate any effort.

I am still unable to find who the artists are whose voices are heard at the end of the attraction, but the song was recorded by They Might Be Giants for the credits of Meet the Robinsons.

I will keep looking now because you have piqued my curiosity!

Do you mean who sang the song or who wrote it? The Sherman Brothers wrote the song I believe.

MagicMom---thanks! also glad to hear someone else is also curious

LivLuvsTink---thank you, but I meant who sung the song at the end of the Carousel of Progress