True Stories "Beer Barrel Polka"

My wife and I were attending her cousin’s graduation, from grammar school, in a small logging town in northern California. The graduating class had 30 graduates. As the parents and other people arrived and were seated, the time for the processional came closer.
I noticed the principal was nervously looking at his watch and checking out the front door. He finally announced the regular pianist had not gotten there and asked if anyone in the audience could play the piano. No one said anything until one lady meekly raised here hand admitting she could play the piano.
Soon the graduates were marching down to aisle to the tune of the “Beer Barrel Polka”, the only song she knew!