GUYS. VIOLINS.
I had an entirely shit week, (my cat is super sick and we've been in the vet like a revolving door, goodtimes), and while I was making boozy cake my Pandora ran through a ton of Lindsey Stirling music. AND THUS THE NEW HEADCANON WAS BORN.
Ok, so imagine a random planet the paladins go to that requires a test of cultural exchange as a good will gesture. The paladins (namely Lance), start arguing and debating over what they can do.
Keith and Shiro are just kind of staying out of firing range and notice a bandstand type deal off to the side. On it they find the alien equivalent of a violin and guitar amongst other kinda similar instruments.
Queue Keith and Shiro just picking up and starting a back and forth battle with Keith playing violin and Shiro the guitar. And there was much shock and rejoicing from the paladins/natives.
Bonus points for Keith and Shiro dancing with eachother while playing. Keith spinning around and hooking a leg over Shiros hip before body rolling away, Shiro going back to back with Keith and sexy grinding. Or have it just be fun. Or martial art based. Whatever. Make em move.
Anyway, that's all I've got. I'm going to go get drunk off cake.