"short" list:
Director/Founder of King's Post (contemp. a cappella ensemble),
former director of TiTones/Evolution (MS/HS a cappella)
Treasurer of the Contemporary A Cappella League
former lead with Carolina Vocal Express (barbershop),
former VP for Music /baritone with the Virginia Gentlemen (barbershop)
(defrocked for singing too many 9s)

Non voice stuff:
Virginia Tech Grad ('92)
Almost a music minor in French Horn performance
Former NASA aerospace engineer (still build/fly amateur rockets)
Owner of structural (architectural) engineering consulting firm for ~15 years.

"If it's not broken, it's probably worth taking apart to see how it works. If you can't get it back together afterwards...well, you can always use spare parts to building something better."