Mark O’Connor, photo by Jim McGuireThere have been many seminal groups in jazz history, whether it be Duke Ellington’s orchestra, Art Blakey’s long running Jazz Messengers, or the classic groups of Miles Davis or John Coltrane. Each of these — plus a host of others — is responsible for laying a unique brick in the pantheon of American jazz. Europe has a younger but equally vital jazz tradition, and one group is largely responsible…