I'm a saxophonist and know plenty of information regarding my own instruments, but I planned to start out playing Viola and\or Violin before I played Saxophone, but it never happened. Since I never bothered to learn the instrument, I don't know much about either one of them. Anyway, I've been thinking about taking up the viola lately, but through the research I've done I've notice they vary in lengths from around 12" to 17" (give or take, I don't know how precise that is). So I was wondering, why are violas made to different lengths and sizes, and what differences do they make to how the instrument is played? Why are violas built to different lengths, and how does that affect the sound? Also, if I were to start playing the viola, what would be a good instrument length to start out with, and what are some good sturdy models to look into that will deliver resonable sound quality and ease for the student player, preferrably at a low price? While I'm a very well-seasoned sax player, string instrumnts are all new to me, so any advice and knowlege, tips and what-have-you would be very much appreciated. Thank you.