The Israel Philharmonic Orchestra A Gala Concert with Zubin Mehta, Daniel Barenboim and Pinchas Zukerman Mann Auditorium, Tel Aviv For nearly two weeks, Tel Aviv's Mann auditorium has served as the venue for perhaps the world's most impressive classical music line-up, whose members have convened to celebrate the Israel Philharmonic Orchestra's 70th anniversary. Featuring an astonishing array of top-notch musicians, the concert series has offered a number of memorable musical experiences almost every evening. Tuesday's gala concert brought together three of the IPO's closest friends: musical director Zubin Mehta, pianist Daniel Barenboim and violinist Pinchas Zukerman. Like the concert series' other guests, the three appeared free of charge, donating their expertise and reputation in honor of the orchestra's seven decades. Mehta, almost needless to say, conducted the entire program by heart. This phenomenal conductor has almost the entire Romantic repertoire stored securely in his head, and this was another golden opportunity to demonstrate it. With a completely packed concert hall and television cameras broadcasting the concert all over Europe on the French/German Arte network, the concert had a special festive touch even before the first note was played. (One of the evening's few shortcomings: the long concert was performed with no intermission due to broadcasters' demands, challenging many of the patrons' bladders.) The opening piece was Bruch's arresting Violin Concerto No. 1, which was wonderfully performed by Zukerman with Mehta's authoritative conducting to support him. Next up was Ravel's "La Valse," a symphonic poem that employed the entire orchestra. The dramatic piece was probably the evening's apex, featuring the IPO at its most controlled, colorful and precise and highlighting Mehta's superb technique and command of his beloved players. Concluding the evening was Brahms' enormous Piano Concerto No. 1, one of the most emotionally charged pieces in the entire Romantic repertoire. Expected to be the concert's high point, it turned out to be less exciting than one might have hoped. Having endlessly played for the last few days, including at a demanding recital just the night before, Barenboim was not in his best form for this concerto. In contrast to his usual, flawless playing, the Argentinean-born pianist erred during the first movement, and his overall performance dipped below his normal standards. Nevertheless, Barenboim was still exciting and emotionally convincing even in less than perfect form, especially in the concerto's soft, dreamy second movement. Special kudos must go to Mehta, who quickly recovered from the mistake in the first movement and provided a powerful, electrifying accompaniment throughout the concerto. The IPO's celebratory concert series will come to an end Sunday with a New Year's Eve performance of Beethoven's Ninth Symphony conducted by Kurt Masur.