If you emailed it to anyone else and they didn't reply right away or at all. Would it bother you or is it just him?

Its just a song. I hate making it sound meaningless because it has meaning to you but it's seen differently in general than sending a regular email asking for stuff etc

It probably isn't a issue to him, again he isn't big on music and maybe he felt pressure with it. I personally would not bring it up and see if he does. I know you probably will though but try to not take it personally.

Maybe this t is not the kind of t to do random emails with. Maybe it is better to just generally discuss what the song means to you regardless if he hears it

Example.... if a friend told you about a movie that meant something to them but say you were not big into movies or a specific kind of movie but the person told you verbally how the movie impacted them, is that still meaningful? I'd say so. Songs are personal especially and different songs mean different things to people. Just tell him why its so important, even if he chooses not to listen and he has that choice, he can still hear your story and see the emotion. For therapy especially that should be enough

Try not to put standards on people so much. Not replying to a song link is not a huge thing. There could be many reasons one of which could be maybe he is saving it for session