The Dom in Köln am Rhine.   We were invited to do a broadcast for BFN in Cologne by Bill Crozier who later handled the popular Two-Way "Family Favourites" for the BBC.   He loved his jazz, was a fine pianist, and booked us into two jazz cellars in Cologne.   These were the infamous "Tabu" and "Boheme" clubs.   (Thanks to Maurice Gavan.)