Will do, Buttercup.
I have never seen Fledermaus, though I've heard it on the radio. The overture always makes my heart beat faster. I think it's Johann Strauss's first operetta, and it just radiates the energy of a new beginning. There are four pieces that give me this feeling: the Fledermaus overture, the overture to Smetana's The Bartered Bride (pretty much the start of Czech national music), the overture to Glinka's Ruslan and Ludmila (Not his very first opera, but close, and Glinka is the father of Russian national music), and the first notes of Schuman's first symphony, the "Spring."