It's hard to believe, but the Bach Choir of Pittsburgh is 75 years old, a monumental achievement for a one-time church choir. To celebrate, Peter Karlovich and Steve Herforth hosted a BACHday Bash at their home on Mount Washington Saturday. Choir members and guests took in the bird's-eye views of the Golden Triangle while they mingled among the silent auction treasures, enjoyed fine wines and sang happy birthday to Bach.