Leonard Bernstein was as much a teacher as a conductor and composer. Now, his musical grandchildren have taken the stage, and perhaps just in time for classical music. This weekend, two impressive young conductors - men about to take on the awesome responsibility of leading orchestras in the US's two largest cities - paid tribute to Lenny with Carnegie Hall concerts celebrating the late maestro's 90th birthday season. On Friday, the 41-year-old Alan Gilbert led the New York Philharmonic in a commemoration of the 65th anniversary of Bernstein's first major triumph with the orchestra he went on to lead from 1958 to 1969. On the same stage on November 14, 1943, the 25-year-old Bernstein created a sensation - and front-page news the next day - by filling in for the ailing Bruno Walter in a national radio concert. On Sunday, the 27-year-old Venezuelan Gustavo Dudamel led the Israel Philharmonic in two works by Bernstein, plus one of Bernstein's favorite symphonies. It's too bad Bernstein, who died in 1990 at age 72 - wasn't around to witness this juxtaposition of masterful young talent. Gilbert was five when the last of Bernstein's Young People's Concerts was televised in 1972; Dudamel wasn't even born to witness the iconic series that brought classical music to the baby-boom generation. Gilbert, chief conductor of the Royal Stockholm Philharmonic for the past eight years, is moving from Sweden to his home town next fall to become the New York Philharmonic's music director. Dudamel, who has been music director of the Gothenburg Symphony, also leaves Sweden for the US West Coast to take the same position with the Los Angeles Philharmonic. They face great challenges - more immediately the hemorrhaging economy and then the aging demographics of the classical music audience. On Friday night, the music flowed with power and sensitivity. Gilbert led an all-Bernstein program featuring the Symphonic Suite from On the Waterfront, Serenade (after Plato's Symposium), with Glenn Dicterow as solo violinist, and eight songs from West Side Story with soprano Ana Maria Martinez, tenor Paul Groves and the New York Choral Artists. Waterfront was filled with the violence and romance of Elia Kazan's 1954 movie starring Marlon Brando and Eva Marie Saint in a story about an ex-boxer's fight against union corruption. Jumping and with big sweeping gestures, Gilbert ratcheted up the tension to near frenzy. He stabbed the air with his baton during its percussive punches, and when the music got suddenly quiet, he collapsed into a crouch. By the end, his dark straight hair was spiking above his forehead. Dicterow performed effortlessly in the Serenade, and Groves and Martinez captured the passion of the ill-fated lovers Tony and Maria in the songs. In the orchestra's own fitting tribute to Bernstein, the musicians played his overture to Candide for the first encore. With the audience still standing and Gilbert off stage, concertmaster Sheryl Staples gave the downbeat, and they played it without a conductor, as is their tradition. In the final encore, Gilbert led the orchestra and singers in a spirited performance of "Mambo" from West Side Story. To the audience's delight, he turned and signaled them to shout "Mambo." On Sunday, it was Dudamel's turn. To his regret, Dudamel never met Bernstein. "I'm very sad because he was a special character," he said in an interview with The Associated Press. "One of the best, if not the best. And he's an inspiration for me. He was a magic man... I love to play his music." The concert began with Dudamel leading a haunting performance of "Halil," a flute concerto Bernstein finished in 1981 in memory of an Israeli flutist killed in the 1973 war. With its mix of dissonance and tonalism, outbursts and quietude, the music depicts the horrors of war and the craving for peace. The soloist, Eyal Ein-Habar, played the difficult and almost nonstop part with technical dexterity and great sensitivity. Next was "Jubilee Games," which Bernstein composed 22 years ago for the Israel Philharmonic - which he often led, perhaps most memorably in Beersheba during the 1948 war and on Jerusalem's Mount Scopus after the 1967 war. As an orchestra member told the audience: "Lenny was one of us... He knew us in and out, and 'Jubilee Games' is us - noisy, undisciplined, energetic and unpredictable but also sincere, intimate and profound." That's an ideal script for Dudamel, who stirred the pot of chaotic cacophony, his long curly locks bouncing as he pirouetted on the podium. He danced his way through jazzy sections and brought out the introspective parts with rabbinical soul-searching. The final piece was Tchaikovsky's Fourth Symphony. Dudamel led a galloping account of the work, one of the war horses of the repertoire. He wielded the baton as if it were a matador's sword. At times it was hidden behind his tails, moving slightly as he conducted with his head and shoulders. His dance steps teased the bull into submission. At the rousing conclusion, the audience howled in delight and jumped out of their seats. In three curtain calls, Dudamel coaxed the Israeli musicians to take their well-deserved bows, but they demurred - directing the cheers to him.