Sorry. It's a black powder meet.
Traditionally, rendezvous was a gathering of mountain men during the fur trade era (about 20 years of our history right before the '49 Gold Rush). Mountain men from miles around would gather at a designated meeting place and exchange their furs for powder, lead, food, supplies and alcohol. The smart traders deferred trading until they got the trapper drunk, and then they could trade dirt cheap. They had shooting games, camp tales (lies), horse racing, etc. as entertainment (didn't I mention alcohol?).
Modernly, it's a meeting of black powder shooters and some are "theme" oriented (French Indian War, Revolutionary War, Fur Trade Era) and where the shooters are sparse, you come as you are (regardless of era). Some suttlers (traders) show up and hawk their wares (tomahawks, trade beads, leather, horns, pouches, bullets, gun parts). The better rendezvous also have blackpowder shooting games including a trail walk, hawk (tomahawk) throw, archery. The shooting games are more fun (for me) than regular rifle shooting.
If you're anywhere near Friendship, IN, go to that one in June. It's the mother of all Rendezvous. Check out the National Muzzle Loading Rifle Association as they list the Rendezvous in their magazine, Muzzleblasts.