He served as concertmaster of the Metropolitan Opera orchestra for 43 years; upon his appointment in 1957 at age 26, he was the youngest person to ever hold the post.
[2] Gniewek was a native of New York City where he began his musical education; he continued at the Eastman School of Music, studying with Andre de Ribaupierre and Joseph Knitzer, becoming concertmaster of the Eastman-Rochester Orchestra and associate concertmaster of Rochester Philharmonic Orchestra under Erich Leinsdorf.
Other teachers were the Canadian violinist Albert Pratz and Raphael Bronstein of New York City.
[4] He was formerly married to ballet dancer and Pilates instructor Lolita San Miguel.
[5] His sister is Cecilia Brauer who plays celesta and glass harmonica in the Metropolitan Opera Orchestra.