At first glance, the Israel Festival’s opening concert of its classical music program seemed neither particularly attractive nor sensational – the Hagen Quartet had already appeared in the Festival several years ago (a fact carefully left unmentioned in the program notes).However, there cannot be too much of a good thing.Sounding remarkably more mature now, the Hagen Quartet now represents the glorious tradition of Central European chamber music at its very best. In particular, its delicate nuances of dynamics are outstanding, and its capability of producing a soft, almost inaudible piano is a veritable rarity. This created a surprise effect at the conclusion of Haydn’s String Quartet op. 54/1 after an exuberant fast final movement and then again at the end of Bartok’s String Quartet Nr.2.The program’s highlight was Bartok’s rarely performed quartet. It was performed with gripping, almost painful intensity.In Brahms’ Piano Quintet, Arthur Rubinstein Competition First Prize winner Kirill Gerstein joined the Hagen Quartet. It seemed as though some more rehearsals might have brought the pianist and the quartet to a somewhat more consolidated common ground of performance.