I suggest that you could've prevented most of this by asking your son to stop playing his trumpet. Two hours is way too long. It does get on other people's nerves. It's healthy to stop the playing when it upsets others.
I also suggest it was rude to your neighbors to tell him to play outside. They would have cause to complain.
I understand your wanting him to learn and thinking that the more he plays the better it is for him. But you have to also consider other people's needs.
I suggest that rather than having more creative punishments, you need to have better boundaries so that you stop the behavior before it gets out of hand. Send the boy to his room with the first sign of disrespect.
Have a family meeting and all of you decide on some basic rules. Number 1 for me would be to always show respect to everyone. I would say that once something disrespectful is said that the person goes to their room to adjust their attitude. They can do whatever they want in their room but they don't come out until they can apologize for their misbehavior.
Doing additional chores is a good idea, too.
What is most important is to have some clear rules and immediate and consistent consequences for breaking them. Immediate, meaning that you don't let the situation escalate to the point that everyone, especially you feels out of control.
I suspect that because you felt grumpy you let this situation go on for too long. Grumpy is a legitimate feeling and you have the responsibility to handle situations that are increasing your grumpy feelings. Do not let the kids take advantage of you because you feel guilty. It is normal for you to be grumpy. Expect your boys to recognize that they need to alter their behavior when you're more sensitive. It's called empathy. You want to teach them how to recognize and get along with all sorts of moods.
Here's an example. I was visiting a friend and her 3 yo son. The boy kept interrupting his mother who was sewing. After a couple of times of getting him involved with another activity, she looked him in the eye and said, "I'm getting cranky. I need to finish this. You go over there and stay until I'm finished." I was surprised. I'd always thought that mom was to be all patient and meet the needs of the child first. This was an eye opening for me that changed the way I looked at meeting needs.
If mom's needs are not being met, she cannot meet the needs of her children. At 3 this little boy accepted his mother's directions, went to the other side of the room and played quietly. When mom finished she went to him and thanked him for being cooperative.
You have to take care of yourself, first. It's reasonable to stop the trumpet playing. None of the rest would've happened if you had.
Now that the trumpet is dented, the boy who shoved and caused the damage should pay for that damage. Make the consequences fit the misbehavior. It would even be reasonable to have him pay for a new trumpet.
After your SWH: When you got in his face and yelled at him you were doing the same thing you were telling him not to do. You need to step back and cool off before you handle situations. You are teaching by example.
I understand his unwillingness to open up to you. He most likely doesn't respect you because you act just like he acts. He won't trust that you can help him manage his behavior until you're able to manage your own.
I suggest family counseling to get your family back on track. Sounds like anger is the norm. You need to find a way to calm things down.
You and your boys are in a power struggle. He's hard headed. It sounds like you're equally determined as he is to make this go your way. Can you develop some empathy for his position? Can you find a way to be on his side so that he can be on yours?
You have open war now. Nobody wins when there is a battle of wills.
Both parents and kids lose. Kids don't learn appropriate behavior and parents are chronically in fight mode.
Later, I would not strip his room. Everyone needs a place of their own in which to feel safe. He has lots of legitimate reasons to be angry. Stripping his room just gives him another reason to be angry.
Instead I would make his room a place in which to be quiet and cool down. Music calms, universally. I would be sure he has some way to listen to music. I would teach him how to manage his anger. One way to do that is to provide him with a safe place in which to calm down. Then be sure to send him to his room before anger takes over.
When you're beginning to feel the need to yell, tell you son that you're getting angry, he's misbehaving and therefore he has to go to his room. Then give him "the stare" until he goes there. This will only be effective if you can remain in control of your own emotions.
Yes, take away privileges, TV and computer time but be sure he does have a place that he can go to cool off.