Cecil Forsyth's Orchestration offers a very thorough analysis of possible double, triple and quadruple stops. It was written in 1914 but I believe the rules for "safe" string writing haven't changed that much, so I think it is a good idea to encode those rules into a validator that can be selected from the UI.
Cecil Forsyth's Orchestration offers a very thorough analysis of possible double, triple and quadruple stops. It was written in 1914 but I believe the rules for "safe" string writing haven't changed that much, so I think it is a good idea to encode those rules into a validator that can be selected from the UI.