Is it appropriate to answer questions with accepted answers and to upvote other answers?
Just because a question has an accepted answer doesn't necessarily mean it's the best answer. Occasionally, I've seen accepted answers that were inaccurate! All it means is the OP decided that answer was the most helpful/appropriate/useful one out of the bunch - at that time. It's the case that sometimes really good - far better- answers have been provided later, and the OP hasn't picked up on them, so the 'accepted answer' remains accepted.
If someone feels they can add extra quality and information apposite to the question, then yes, get another answer down. Or if a question reminds you of something similar and related, but not exactly the same, then yes, ask another, related, question. We'll soon decide if it's a dupe! Similarly, if you find answers (and questions) which contain misinformation, or are not as clear as they could be, leave a comment, or even edit accordingly. And upvoting is very acceptable, to all of us. From a personal angle, downvoting is also acceptable, but makes little sense when no valid reason is offered alongside it.
Yes, of course! There are multiple reasons why, but I'll highlight just two for now:
- Remember that the original poster (OP) is the one that accepts the answer. They can accept an answer whenever they like, meaning that they can accept a sub-par answer that lacks the type of detail we like to have at this site. Other answers can then fill in this detail if the accepted answer is found to be lacking.
- There are often multiple ways of addressing an answer in music theory. Even if an answer has already been accepted, it's helpful to have additional answers that approach the solution from a different way.
We do strive, however, not to have extra answers that just repeat information already given in another answer. Not only does this clutter the site, it could confuse some learners if they're trying to discern a difference between two equivalent answers.
But if you have new information to share, definitely feel comfortable writing a new answer!
Richard makes some great points. Another reason that it might be appropriate to upvote answers that aren't accepted might be if the accepted answer helps OP specifically, but other answers are also helpful, particularly when the question is a problem OP needs to solve, and one answer solved it for OP but others are equally valid or helpful to others.
It is never improper to add quality answers to a question, regardless of the age of the question or whether an answer has been accepted, but try to avoid simply restating what others have said.
It's also never inappropriate to upvote quality answers. Don't let a checkmark stop you from voting up other answers!
However, one should avoid asking duplicate questions.