At the request of the Chicago Jazz Festival 2006 vocalist Kurt Elling put together a program around John Coltrane (who would have been 80 years old at that time) and his collaboration with jazz singer Johnny Hartman, which lead to their famous Impulse LPs from 1963. Something like that demands a comparison between Elling now and Hartman then.
sources:
Kurt Elling – Concord 0888072313149
John Hartman + John Coltrane – Impulse A 40