What should I sing for my audition?

My Drama workshop will be presenting Alice in Wonderland jr. soon. I'm a female that has a voice range of a Coltrano Alto to a high mezzo. For my audition I must have a monologue (which I already have) and a song. I want to try out for the part of The Caterpillar and the White Rabbit and Tweddle Dum/Dee. Could I please have some suggestions of songs I could sing for my audition. Thank you :)