 Harpist Ann Hobson-Pilot joined the Boston Symphony Orchestra in 1969 and became its principal harp player in 1980, a position she held until her 2009 retirement. Flutist Benwick Smith was a member of the Boston Symphony Orchestra for nearly 30 years until his retirement in 2006. Performances by both of the longtime BSO colleagues are highlights on Sunday Baroque this weekend. Sunday morning at 7 on WSHU Public Radio.