Both are very good parts. I'd be happy with either one.
*contains/is a solo
Songs Sour Kangaroo Sings In:
Oh, The Thinks You Can Think!
Biggest Blame Fool*
Chasing The Whos*
Horton Sits On The Egg
Egg, Nest, and Tree*
The People Versus Horton The Elephant*
Finale*
Songs Mayzie Sing In:
Oh, The Thinks You Can Think!
Biggest Blame Fool*
Amazing Mayzie*
How Lucky You Are [Mayzie's Reprise]*
Horton Sits On The Egg
Egg, Nest, And Tree
Mayzie In Palm Beach*
The People Versus Horton The Elpephant*
Finale
So there you have it. Even though Mayzie is in more songs, Sour Kangaroo seems to sing more.
Again, both are great parts and you will be happy with both.
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle