A set of bass strings walks into a bar. The E strings says "Bartender - a round of martinis!" Bartender says " We don't serve strings in here - get out!", and they all leave. The A string unravels his threaded end, loops it through his midsection, walks back in, and says "Bartender - a martini, please!" Bartender says "Aren't you one of the strings that was just in here?" The A string says "Strings? No - I'm a frayed knot".