Boyfriend (33M) craps all over girlfriend's (26F) joy: story at 11

TL;DR I wanted to share something special to me with my boyfriend and he could barely manage to care.

Hey y'all, you can call me Tina, and we'll refer to my boyfriend of 9 months as Gary.

First, we'll set the scene: I'm a music teacher (piano/guitar) and I absolutely love what I do. The store where I work had been having a 2 week rock band camp for some of our students, culminating in a performance held at a local venue; so, a bigger deal than your standard recital. I was especially excited because one of my own guitar students was in the show.

The evening of the show arrives, and it just turns into an ordeal almost from the get-go. Gary is on edge because he's kinda stoned and fears that he will have to socialize (gasp, the horror), which he sometimes struggles with even while sober. We encountered some other frustrations (his GPS didn't work in the area, he muddled his order at Taco Bell) and he just fell into this funk. He had to stand outside the venue for like 10 minutes to compose himself.

And then when the performers are onstage, he's either texting or looking up long enough to give like a golf clap. When the show was over and I was gushing about how proud I was of all the kids, he replied, "Yeah, it's great. Hey, this girl messaged me on okcupid and she's interested in dating a couple..." (We're polyamorous, so that isn't as weird a thing to say as it might seem).

I understand his feelings are valid. I understand that he still made an effort. I understand that he isn't as musically inclined as me. What I would like him to understand is that I tried to share a significant part of my world with him, and he didn't seem to care. I told him before we left, "This is important to me, and I want to share it with you because you're important to me."

I take joy in his joy when we do stuff that he likes, but it's apparently more difficult the other way around.