Marian McPartland is a true jazz legend. Since emigrating from England in 1946 with her American husband, the late cornetist Jimmy McPartland, Marian has accomplished more than we have space to even touch on. The nimble 82 year old pianist is not one to rest on past achievements, however, and has just released Live at Shanghai Jazz, on Concord Records, as well as four CDs taken from her popular National Public Radio series, Piano Jazz. Live at Shanghai Jazz is a trio date recor …