Many so-called normal human interactions leave me perplexed. Discussing music is no different.
I’ve been listening to a wider variety of music lately. I guess I would like to chat about music at parties, rather than to sit in the corner all night long.
When music geeks discuss music, what do they talk about? What are common questions that they ask other music geeks about bands and songs? What elements do they like to critique? What type of random comments about music do they like to make?
Everything starts with “what are you listening to, what do you like - and how come?”
Everything past that is finding words that work for you.
eta: so - what are you listening to? Practice on us…
Blues and indie rock. 
If someone wrote down a summary of the discussion, would those be Clef Notes?
Melody, structure, the artistry of the musicianship, the difficulty of the musicianship, musical equipment, the physics involved in making music, the emotional content, the lyrical content, the originality, the connections between the different artists, the history of the genre, the effect of politics or social matters on music, the tribal nature of musical genres, the connection between fashion and music, an artist’s sexuality, the music industry, the art that surrounds music (such as photography, album artwork and music videos), and sometimes we talk about the discussion of music itself such as asking “what do music people talk about when they talk about music?” which is a perfectly valid discussion about music in itself.
Concerts we’ve been in, conductors we’ve played for and soloists we’ve played with and all their idiosyncrasies, things that have gone wrong in performances, weird places we’ve performed…
Nice. Bet that works with music folks at parties. Let’s try again - who and what do you like about them?