My first 20 years, I wore a tux. Nice double classic (i.e. vintage style) double breasted (hate "crumb catchers"), white piqué shirt with patent leather shoes. The wife always said I like I stepped out of a 1940s Bogie movie (which I took as a complement). The past seven years, it's been an inexpensive black suit (JCP brand) with a black shirt and black tie. I'm thinking that my last few years I may just go in a black shirt and slacks like some of conductors of famous orchestras do. I think as long as your appearance doesn't distract from the performance and is venue appropriate, it doesn't really matter.