I have an NS design electric upright with some old, dead Bel Cantos, and I'm thinking about getting some rosin. I haven't bowed in what feels like years, and I'd like to get a new, fresh cake to go along with my Vance method book. The thing is that there are so many different types of rosin, and honestly I don't know what the difference is. I've heard of Pop's, Carlsson's, Oak... and that's about it. I don't have enough experience to know what I like, so I don't know where I should start. My question is twofold - what are the actual differences in various kinds of rosin, and what would be a good place for me to start? For what it's worth, I live in North Texas, but I mostly play in my air-conditioned home (kept in the low 70s and around 50% humidity), and I plan on playing both classical and jazz. EDIT: Actually, I have a third question: do you think the differences in various rosins would actually be noticeable on a solid-body electric upright?