Nothing about cellist Lynn Harrell's two all-Bach recitals last week in Grace Cathedral could be called ordinary, except for his insightful virtuosity. First and most strikingly, those performances of J.S. Bach's six highbrow Suites for unaccompanied cello, BWV 1007-1012, were presented as part of the four-month jazz festival, titled the 9th Annual SFJAZZ Spring Season.