When Lorin Maazel nominated Daniel Barenboim to succeed him as the music director of the New York Philharmonic, he inadvertently called attention to a major challenge facing American orchestras. In suggesting Mr. Barenboim, Mr. Maazel named the person probably least likely to take the job — someone who has explicitly described his distaste for the fund-raising and community-outreach activities in which American music directors today are required to participate. In nominating this noncandidate as the only conductor qualified to lead the Philharmonic, Mr. Maazel thus underlined the dearth of inspired conductors both willing and sufficiently experienced to lead the country’s greatest ensembles. Where are the next great maestros?

Four major American orchestras ––the Philharmonic, the Chicago Symphony, the Philadelphia Orchestra, and the Pittsburgh Symphony –– either are now or soon will be searching for new music directors. Two of these –– Chicago and Pittsburgh –– have been looking for more than two years. When Mr. Barenboim, who is 64, left the Chicago Symphony at the end of the last season, they hadn’t found a successor they were happy with, so they appointed Bernard Haitink, 77, and the grand old man of classical music, Pierre Boulez, 81, to jointly steward the orchestra until they do find one. Pittsburgh held a 15-month search and also failed to find a desirable candidate. They opted instead for a triumvirate –– Sir Andrew Davis, 62, Yan Pascal Tortelier, 59, and Marek Janowski, 67 –– of interim caretakers.

Why have two major orchestras failed to find conductors brilliant enough and willing to lead them? Discussions with several people in the classical music industry yield two general theories. One is that there is a generation gap in the conducting world: There are legendary maestros in their 60s, 70s, and 80s, and promising 30- and 40-somethings who are still building their repertoires and proving themselves, but there’s not much in between, some insiders suggest. The other theory is that the substantial off-podium demands that come with the position of music director, while necessary for the survival of individual orchestras, are in tension with the need to find the greatest artistic talent.

“A great artist like Daniel Barenboim is not trained to schmooze, but he is required to in this job,” the vice president for artistic planning at the Pittsburgh Symphony, Bob Moir, said, alluding to Mr. Barenboim’s much-publicized statements about his dislike of fundraising, at the time he announced his departure from the Chicago Symphony. “The conflicts that the job description creates for artists at his level are serious.”

There are “two bottom line things” in finding a music director, Mr. Moir said. “The primary role of a music director is the artistic life of the orchestra: to set and push the standard of the orchestra. [But] the fact that in the United States the institution has to raise millions of dollars every year to survive means that the star is going to be required to participate by the funding community,”he said.”It’s not that we want to send them out there,” he added. But “the people whom we are asking for a lot of money want to, and need to, have contact with the artistic star.”

Some in the classical world see the conflict between the artistic and nonartistic responsibilities of music directors as somewhat overblown. “I have very little sympathy for any music director of an American orchestra who finds the off-podium demands too onerous,” the director of conducting and orchestral studies at Juilliard, James DePreist, wrote in an e-mail. “These off-podium activities are primarily designed to raise funds which go directly to enhancing the artistic product and the survivability of the institution.” He added: “It is the job of management to organize these fundraising projects in such a way as to respect the music director’s time, and this is demonstrably doable.”

The vice president for external affairs at the Louisiana Philharmonic Orchestra, Sharon Litwin, said she thinks that younger conductors, like the LPO’s new music director, Carlos Miguel Prieto, 40, are more accepting of the expanded job requirements. “Each organization and each individual will determine the level of involvement [by the music director in fund raising and community-outreach] that each can tolerate,” she said. “But I think the era of the grand maestro who comes only to the podium is kind of gone –– in America, anyway.”

In terms of artistic ability, too, many in the industry are pinning their hopes on conductors who are just now emerging. “Every area of the arts goes through phases; one never quite knows what the logic is,” the executive and artistic director of Carnegie Hall, Clive Gillinson, said. “The reality at the moment is there are a lot of wonderful conductors in their 70s and 80s, relatively few in their 50s and 60s, and quite a lot of young talent coming along.”

The editor of the Musical America Directory of the Performing Arts, Sedgwick Clark, expressed a similar view. “There have been a couple of generations of less than inspired conductors,” he said. But he added that there were several talented younger conductors, including David Robertson, 48, and Marin Alsop, 50, the music directors of the St. Louis Symphony and the Baltimore Symphony, respectively. Mr. Clark said he thought that the orchestras looking for music directors, including the Philharmonic, should “take a leap of faith for a younger musician and help them along.” But he acknowledged that the younger generation is still developing.

“I like David Robertson’s conducting very much. Is he ready for the Philharmonic? I’m not sure,” he said. “He’s in a very good place right now out in St. Louis,” he continued, and “maybe in a few years, he’ll be ready for a big orchestra like Chicago, like the Philharmonic, like Cleveland, like Philadelphia.”

Mr. Moir also said he thought the rising generation of conductors showed great potential. “There’s a surprising number of people in their 30s and 40s who are showing extraordinary promise,” he said. “It is so much more encouraging than it was five years ago.”

Perhaps these young people will fill some of the major positions that are now open. The Pittsburgh Symphony’s triumvirate is engaged until the end of the 2007–2008 season; the symphony is in the process now of evaluating how the system has worked. The Chicago Symphony’s spokeswoman, Synneve Carlino, said their search committee will take however long it takes to find the right person. The spokeswoman for the Philadelphia Orchestra, whose music director, Christoph Eschenbach, 66, recently announced that he will leave after the 2007–2008 season, declined to comment on their search process, as did the spokesman for the New York Philharmonic, Eric Latzky. But the clock is ticking. In two years, we should know who America’s next great maestros are, or will be.