I have put off asking this, hoping I'd figure it out on my own.
A violin has four strings. When you keep your hands off the strings, they're tuned to G3, D4, A4, and E5. That's what "open strings" means, I thought. So playing "open strings", you would have only four notes available. But the "open strings" patches let me play any note, so I'm misunderstanding something basic here. How do the "open strings" work when I'm not playing G3, D4, A4, or E5?