So I'm in a "variety" cover band that's about three years into its run and picking up some good momentum and has a good following. The market we play in is pretty small and a lot of musicians in various bands know each other and check out each others' shows. This past weekend we allowed a couple of guys from other bands to sit-in with us on a song or two. This turned out to be a very bad decision as the "guest guitarist" was ridiculously drunk, started the song in the wrong key and butchered the lead so bad that our drummer ended the song prematurely on purpose to get him off the stage. This happened at the top of the set and the whole rest of the set was a disaster even after we got the guy off stage. The guest drummer didn't do quite as bad but was also very drunk and made us sound like a very mediocre band on a couple of songs we usually play very well. My band has agreed we need to adopt a "policy" on sit-ins but we are debating how hard of a line to take. Option 1 - "Nobody sits in, ever." Option 2 - "If we know you, you're good enough and you're not too drunk to play you can have a song or two." Normally I would think Option 1 would be a no-brainer and that is my personal preference, but I think one or two of the other guys in the band are leaning toward the more lenient policy cause they sit-in themselves with other bands and feel we should not be above reciprocating. It's kind of important in this market to keep good relations with other bands in terms of referrals, etc. Also for example my drummer sometimes likes to let another guy sit-in so he can go out and hear how his kit sounds (since we don't have a soundman, we mix from the stage). Thoughts?