Well, thinking it over we have some early classical representation anyway, and Beethoven will probably get another song up here anyway...
So I'll swtich the Sonata vote to..."Let it Be" and "Strawberry Fields Forever" are both tempting, but will likely find some other wupport, at least one...I can't think of a really good pucini part by itself, he's my favorite, but his arias bleed togetehr for one big powerful movement (part of why he's my favorite, or a favorite, Tchaikovsky being the other, adn he has the same issue, to a lesser degree but still his melodies are best without the singing) so I'll let in maybe an overlooked gem.
I'll take "I've Got A Little Lsit" by Gilbert and Sullivan...hilarious song, great tune, and you can adapt it for jsut about anything...