PHILADELPHIA — Bernie Wilson, baritone member of the rhythm and blues group that produced the 1972 hit “If You Don’t Know Me by Now,” has died.

Wilson, 64, died early Sunday at Kresson View Center in Voorhees, N.J., following a stroke and a heart attack, his cousin, Faith Peace-Mazzccua, said Monday.

Philadelphia International Records, the former record company for Harold Melvin & the Blue Notes, said Wilson’s death leaves Lloyd Parks as the sole surviving member of the group’s lineup at the time. The lineup also featured Teddy Pendergrass and Lawrence Brown. The group produced a string of R&B hits in the ‘70s and helped define the Sound of Philadelphia.

“If You Don’t Know Me by Now” topped the R&B charts and made the top five on the pop charts. The hits that followed included “I Miss You,” “Bad Luck,” “Wake up Everybody,” and the dance track “The Love I Lost,” which has been credited as one of the first disco records.