Frederick J. Knapp, 84

Frederick Joseph Knapp, a singer and musician who had a career in industrial shows and, with his wife, the former Penny Leka, later founded a company that trained businesspeople in public speaking, presentation, and dress, died of a heart attack in Northport on Nov. 13 at the age of 84. The couple recently sold a house in East Hampton they had owned for 24 years.

Mr. Knapp left a Sears management program in the 1960s to take roles in industrial television and film commercials. He was the M.C. or lead in over 50 Broadway-style shows, and introduced  new Buicks and Fords to dealers, including Lee Iacocca’s first Mustang and Honda’s first car in America.

While working with Ford, Mr. Knapp jumped on a suggestion from an executive to establish a consulting firm. Frederick Knapp Associates, which was based on Madison Avenue, trained some 31 top executives from 29 countries and 64,500 managers over the next 31 years. The company worked with AT&T, John Deere, Bacardi Rum, Nabisco, and Philip Morris, among others.

Mr. Knapp and his wife, a violinist, met in New York City and were married on Dec. 18, 1965. They enjoyed working together in the consulting business but also entertained on cruise ships from time to time. “We were so happy together, we didn’t want to be apart,” Mrs. Knapp said.

He was born on April 9, 1930, in Superior, Wisc., to Frederick D. Knapp and the former Helen Haremza. A brother, Robert Knapp, and a sister, Larraine Hurd, died before him. He grew up in Shell Lake, Wisc., and went to the University of Wisconsin, where he received a degree in economics. He also did postgraduate work there and at Columbia College in Chicago. He had served as an Army officer during the Korean War.

Mr. Knapp joined Sears, Roebuck & Company, working in Wisconsin before he was selected for the management program at Sears headquarters in Chicago. He then moved to New York City to pursue singing and acting.

He was a member of the Screen Actors Guild, the American Federation of Television and Radio Artists, and the American Society of Training and Development.

At the age of 49, Mr. Knapp began to experience problems with his sight, and in 1992 he became legally blind, though he maintained peripheral vision. He served two terms as the president of the Blinded Veterans Association.

A service will be held at St. Bartholomew’s Episcopal Church in Manhattan, of which he was a member, on Jan. 10 at 2 p.m., followed by a reception. His ashes are to be buried at the Oak Ridge Cemetery in Springfield, Ill.

Memorial contributions have been suggested to the Guide Dog Foundation, 371 East Main Street, Smithtown 11787, or to Pianofest, P.O. Box 639, Hudson, Ohio, 44236.