I have watched many flash mob videos, some that will give you goose bumps and some that will make you cringe. Some of the most enjoyable performances I have witnessed have taken place outside of traditional venues. I watched a performance on a dock in Honduras with dancers, a few drummers, a shaker made of a turtle shell, and a conch shell horn. A Conch shell horn, you say? Yes. You'd be amazed at what can be played on one. Below is Steve Turre, a trombone player by profession, playing several of them with the United Nations Orchestra. https://www.youtube.com/watch?v=tFQAbr-uYFI#t=11 Near the waterfront in San Diego, I enjoyed a Mexican gentleman in a wonderful costume singing in Spanish and playing the guitar. When you tossed some money into his guitar case, he never missed a beat, singing, "Thank you very much," before continuing his serenade. The video at the top of the page is one I would love to witness in person. It will make you want to grab a set of castanets and get your rhythm on.