Saturday night a capacity crowd filled an Amphitheater brimming with anticipation for one of the summer’s key artistic events: an original inter-arts collaboration among Chautauqua’s major performing arts organizations exploring and presenting a brand-new composite version of Romeo and Juliet, conceived and directed with flair and skill by the Chautauqua Theater Company’s Vivienne Benesch. Despite some rain, busy performance schedules all around and the challenges of rehearsing and coordinating in such a busy venue a project involving 150 artists in the pit and onstage, the evening proved a triumph of vision and organization. The other Institutional artistic entities involved were the Chautauqua Symphony Orchestra, Chautauqua Dance program and North Carolina Dance Theatre, Chautauqua Opera Company, the Chautauqua School of Music and — materializing up near the United Nations flag for a sexy entr’acte of Duke Ellington’s “Star Crossed Lovers,” with Scott Hartman the persuasive trombone soloist — a jazz ensemble from the Music School Festival Orchestra. Where else but Chautauqua could such a feat have been attempted, let alone brought off? Even The Juilliard School (to which many of the artists involved have ties) has neither the institutional structure nor an appropriate venue for preparing and presenting such an ambitious, large-scale venture.