1) Maybe he thought the dog didn't need to be trained by a "professional'? Maybe there is something about the dog trainer that was intimidating to him? The dog trainer was a "her"? Maybe he things males are supposed to be in charge--sometimes dogs appear like they prefer men over women or are more submissive to men. Maybe he had an issue with her femaleness? Maybe he thinks he could train the dog better than she can. Maybe he thought it was your hobby and not his hobby?
I find that most alcoholics like to feel that they can control other people. Maybe he is uncertain if he can "control" strangers so he doesn't want to interact with them?
2) He wants to be the center of attention?
3) He is exerting his importance over the grand-baby? "I don't have to be quiet because it all revolves around me"
4) Maybe back to 1), or maybe he is shy, or maybe he was an only child, maybe he sees the pool-people as your hobby?
5) ??

6) ??

Maybe this is a strange self-soothing type ritual? Maybe something significant happened in his life when that music was popular. Maybe it makes him feel like a young stud to listen to Journey? Maybe he doesn't need variety.
I lived with a couple who rented out rooms in their house, they owned a lot of property in houses that they rented out to various people and maximized by building apartments into the basements etc. The woman would talk to the people and do all the coordinating the man would work on the houses. The guy was monosyllabic though. He was also an alcoholic. The only thing I ever heard him talk about in depth was soccer with other men. If people called the house he would utter "Hello, no, yes."" He would hang up without saying goodbye and he often looked at the phone like he had never seen one before??? He never cooked for himself. He never cleaned. NEVER. I think it was a chore for him to shower.
My mother's husband is an alcoholic and I've only ever seen him enjoy talking to his son. He never tried to have a conversation with me, I don't see him speak very much to his own daughters. He likes to talk to certain guys. When he does talk it's rather ceremonious as if he has something wise to say--or like he is sure that his opinion is valued more than other's opinions. Maybe he only likes to talk to males that look up to him. He will discuss mundane stuff with my mother when company is around as if the company isn't there--it's because he would prefer that they are not there. He basically has a small world, watches television all day. He dislikes going to my mother's sisters house for Thanksgiving or Christmas but he does. It's an effort for him to be polite. He would rather watch TV, drink, have my mother cook for him, go kill some deer, go to gun shows...There are probably a lot of men that are like this? My mother thinks she is really lucky because she says he cleans up after himself.
You probably mean that you are just sick of his oddities and he is on your nerves because he isn't helping you enough or participating in your healing.
Sorry that he isn't being more supportive and on the same page with you.