Marathon concerts, such as pianist-composer-commentator Gil Shohat presented of Mozart’s works at the Israel Festival, were a sensational novelty in the 1970s, when conductor-composer Lukas Foss introduced them here for the first time. Some 45 years later, the novelty has worn off. The audience consequently voted with its feet. The two intermissions in the five-hour long concert were spent by the audience searching for a non-existing buffet.The section entitled Lieder (“songs”) included one lied only, “The Violet.” All the rest were opera arias and duets accompanied by a piano substituting for an orchestra. This was unprofessional programming since there exist quite a few Mozart lieder with an original piano part.Outstanding among the 20 works performed by 18 musicians were five pieces sung by the Vocal Octet in Swingle Singers style. Their soft, delicate voices, perfect coordination, remarkable transparency and discreet humor were a pure delight and a welcome deviation from the standard program. So was Omri Mor’s rendition of the C minor Piano Concerto’s first movement, with a cadenza of his own in a refreshing, imaginative and highly virtuoso jazz style, and a brilliant jazz version of Mozart themes, in collaboration with Shohat on the second piano.