HE WAS A South Philly kid who made good.

Joseph de Pasquale set new standards for the viola, playing for the Boston Symphony and, more famously, for the Philadelphia Orchestra in a career of performing and teaching that began at age 15 and ended with his retirement in 1996.

He died yesterday at the age of 95. He lived in Merion Station.

Joseph and his brothers, three of whom would comprise the world-renowned De Pasquale String Quartet, were born in South Philadelphia with the sound of classical music ringing in their heads.

Their father, Oreste de Pasquale, who made his living as a cabinetmaker, was a fair violinist in his own right. He wanted his sons to play stringed instruments and started Joseph off as a violinist.

He learned as much as he could from his father, then began studies with Lucius Cole, Philadelphia Orchestra violinist and father of the celebrated cellist and teacher Orlando Cole.

From there, Joseph went on to the Curtis Institute of Music. He auditioned as a violinist, but viola teacher Max Aronoff thought he should switch to the viola.

Why? Because he was built for it.

He had long arms that enabled him to grip the larger instrument, and a wide stretch in his left hand for better fingering.

Joseph once said that Aronoff told him he could guarantee that he would be the principal violist in a major orchestra.

It was a prophecy richly fulfilled. Joseph de Pasquale became one of the most famous and most sought-after viola players in the world.

When Joseph was nearing his 90th birthday, his former student Stephen Wyrczynski, chairman of Indiana University's string department, wrote in the Journal of the American Viola Society:

"Sound is the means by which music expresses the complex range of human experience. The quality and uniqueness of sound distinguishes the orchestra instrumentalist from the world class artist.

"Legendary violist, Joseph de Pasquale . . . has employed his sound for decades to achieve an unparalleled career as a performer, as well as pedagogue.

"His sound combines the burnished richness of the cello, the brilliant virtuosity of the violin. It is this range of expression that has placed his live performances and recordings at the highest echelon, not only his viola playing but also of string performance, in the current and past century."

Joseph was a highly acclaimed teacher. He began teaching at the New England Conservatory in Boston, but returned to Philadelphia at the invitation of the great violinist Efrem Zimbalist, former president of the Curtis Institute.

His teaching method was to play along with his student. "His teaching centered on the student imitating him on the phrasings and nuances of a particular work or passage," Wyrczynski wrote.

"There is no substitute for listening and absorbing first-hand the scales, etudes, and viola repertoire, even as the student is encouraged to develop his or her own style of playing."

Joseph also taught at the Peabody Institute, Indiana University, the New England Conservatory and Tanglewood Institute.

Many members of other important orchestras studied with him, as did two-thirds of the Philadelphia Orchestra's viola section.

The De Pasquale String Quartet gave Joseph and his brothers - all members of the Philadelphia Orchestra - the chance to hear their music outside the overwhelming mass of the full orchestra.

The quartet comprised brothers William and Robert, violinists, and, until his death in 1972, Francis, a cellist.

When World War II broke out, Joseph joined the Marine Corps. He was stationed in Washington, D.C., with the Marine Band.

While playing with the Boston Symphony, Joseph met his future wife, Maria, who was a descendant of Napoleon's first wife, Josephine, and Russian Czar Nicholas I. She renounced her title of duchess in 1949 to become a U.S. citizen. She died in 2005.

He is survived by two daughters, Maria Alexandra de Pasquale and Elizabeth Ann Giordano; a son, Charles N. de Pasquale; two brothers, Robert and John, and 10 grandchildren. He was predeceased by another son, Joseph S. de Pasquale.

Services: A memorial is planned for the fall.