I have been playing viola for about 5 years. I play in two local orchestras; I also play violin in another local orchestra. My main instrument, however, is violin. Since it is a hassle carrying two instruments to orchestra rehearsals, I have recently purchased a 5 string violin so I can play viola or violin and only carry one instrument. It has given me a few challenges in that I have to remember to avoid the last string, either E or C depending on which instrument I am playing. Practice makes perfect!