David B. Glancey, 74, of Philadelphia, a longtime city Democratic Party chair who headed the Board of Revision of Taxes for years and then became a lobbyist for the University of Pennsylvania, died Monday, Jan. 28, at Pennsylvania Hospital of pulmonary disease.

Mr. Glancey played many roles during his long career, which began in the early 1970s, acting as aide, adviser, and, later, mentor to generations of politicians.

He is best known as a member and chair of the Board of Revision of Taxes, which oversaw property assessment in the city. Mr. Glancey served on the board from 1983 until 2007. Early warnings he sounded about the inequity and failings of the system eventually led to change in 2013.

In political circles, the tax board was known as the “Elephants’ Graveyard,” offering a paying job with few duties that often went to former chairs of the Democratic Party. For decades, the job required little work and perhaps 20 days of meetings each year, his family said. But Mr. Glancey, they said, took the unprecedented step of showing up for work every day, running the staff and mastering the labyrinthine world of property tax and assessment law.

His full immersion in the job surprised no one. “Whatever he did, he took it on 100 percent or more,” said his wife, Alice Reyes. “Monday through Friday, he did his job at his desk, but on Saturday he would sit at the dining room table working on the following week.”

He applied the same thoroughness to his last job as a lobbyist in the Office of Government and Community Relations at Penn, which he held from 2008 until his death. Officially, it was a three-day-a-week job, but his wife said he put many more hours into it. “He took it seriously,” she said.

Mr. Glancey worked in Philadelphia politics for nearly 50 years. Friends described him as “selfless” and “passionate." He did not hold grudges or keep an enemies’ list, they said.

Neil Oxman, who heads the political strategy firm Campaign Group, said he worked with Mr. Glancey for the first time in 1978, during Robert P. Casey’s unsuccessful bid to win the Democratic nomination for governor.

“The amazing thing about him was that, unlike a lot of other people in this business, he never got cynical about anything, and he was one of the few people I know without guile,” Oxman said. “He really was an honest broker and never had an agenda, which is why everyone liked him and he kept his friends forever.”

The only time Mr. Glancey ran for public office, he was defeated. In 1981, he faced State Sen. Joseph Smith in a special election for a congressional seat vacated by U.S. Rep. Ray Lederer, who quit after he was ensnared in the Abscam bribery scandal.

Born in Germantown, Mr. Glancey graduated from Northeast Catholic High School for Boys and earned a bachelor’s degree from St. Joseph’s University in 1966. He completed a law degree at Villanova University in 1975.

He was chairman of the city Democratic Party under Mayor William J. Green III, who led the city from 1980 to 1984. “After I won as mayor, I asked him to be chair of the party,” Green said.

“His unique feature was that everyone liked him, friend or foe,” Green said. “If you were his friend and he sensed you needed help, he was at your side till the battle ended, and usually a key component to making it a victory." The two were friends for 48 years.

When Green’s son, former Councilman Bill Green, ran without Democratic Party endorsement for a Council at-large seat in 2007, Mr. Glancey took time off and put together the political organization that won the primary election. “He came in and worked as if he was being paid,” the elder Green said. “He was a world-class political organizer.”

Mr. Glancey was a born performer with a passion for the theater. He took method acting classes at night at the Wilma Theater and became a teacher and actor there. “He was a card-carrying member of Actors' Equity,” his wife said.

Mr. Glancey was the youngest of nine children. All but a sister died earlier.

In addition to his wife of 27 years, he is survived by a daughter, Allison; step-children Suler Dominic Acosta and Carla Setzler; three grandchildren; and nieces and nephews. His former wife, Catherine, also survives.

A visitation from 9 to 11 a.m. Saturday, Feb. 9, will be followed by an 11 a.m. memorial service at Old Pine Street Presbyterian Church, 412 Pine St. Burial is private.

Memorial donations may be made to the Wilma Theater, 265 S. Broad St., Philadelphia, Pa. 19107, or the Arden Theatre Company, 40 N. Second St., Philadelphia, Pa. 19106.