Stuart Malina was conducting the Florida Orchestra through "In the Hall of the Mountain King" at a Coffee Concert in St. Petersburg when principle percussionist John Shaw went a little wild with the triangle.
The rest of the orchestra was shocked. They didn't know the stunt was planned as a reference to the Geico ad featuring a triangle player taking a solo. Malina took the opportunity to advertise subscription memberships to the orchestra. -via Tastefully Offensive