A frequent visitor here in recent years, the pioneering jazz figure, saxophonist Archie Shepp will be returning for a one-week engagement at the capital’s Half Note Jazz Club beginning this Friday. Shepp, 64, who is viewed as one of, if not the most, articulate and disturbing members of the free jazz generation from the 1960s, and whose harsh, relentless playing reflected social injustice, anger, and the rage he felt, employed a swing-based R&B approach to his music the following decade, and, in more recent times, has mixed straight be-bop, ballads and blues pieces which display little of the fury and fire of his earlier days. The outrage has been replaced by a more celebratory, and at times, reflective, attitude. Shepp, who studied dramatic literature, earning his degree in 1959, turned to academia in the late 1960s, teaching in Buffalo, then at the University of Massachusetts where he was named an associate professor in 1978. During this time, Shepp toured and recorded extensively in Europe, cutting some fine albums with Horace Parlan and Orsted Pedersen. Unfortunately, Shepp’s tone has declined over the past decade, but the artist, who will be fronting a quartet made of Thomas McClung on piano, Wayne Dockery on bass, and Steve McCraven on drums, remains a highly respected, historic jazz figure.