This is a blast! Another of Edition RZ’s great early issues comes up again, presenting pioneering early 20th century conductor and modernist champion Herman Scherchen leading rehearsals for performances of Beethoven’s 4th, 5th, 6th, 7th, 8th and 9th symphonies in Lugano, Switzerland, 1965.As fate would have it, these recordings of Scherchen sniping orders at the RTSI Orchestra (Radiotelevisione della Svizzera Italiana) during rehearsals were spontaneously recorded by sound engineer Dr. Ermanno B…