Venerable D.C. music venue the Black Cat announced today that it will stop selling advance tickets through Ticketmaster, instead switching to competitor Ticket Alternative. The change will become effective September 25, so all shows that are taking place after that date are already on sale via Ticket Alternative. In a strongly worded release, the venue made plain the reasons for the switch: Ticket Alternative’s service charges are lower, typically $2.50 or less for the…