"How can you teach singing without talking about elasticity?" asked Ruth Falcon, a New York teacher whose students include the soprano Deborah Voigt. (You can do both, and many teachers do.)

Yet in the upper echelons of this fractious field, the one thing people seem to agree on is what's going wrong. In dozens of interviews with singers, teachers and administrators around the country, the same complaints emerged again and again. Young singers are not being taught the fundamentals, in particular, the proper use of breath. Breath support, the coordination of lungs and diaphragm, has long been regarded as the key to singing, the thing that sustains powerful voices in huge auditoriums without a microphone. Without it, it's difficult to hit the proper pitches (particularly the top notes), modulate from soft singing to loud, or even be heard beyond the footlights.

The conservatory system where most students start out is self-perpetuating; many of its instructors went right from graduating to teaching without acquiring any stage experience. Many teachers are therefore less accustomed to the acoustics of a big opera house than to the intimacy of a voice studio, where sheer volume can sound alarming -- not at all like the smaller-scaled, lighter voices on contemporary CD's (like Cecilia Bartoli's or, worse, Andrea Bocelli's). Big voices also take longer to mature, and by the time they do, those lucky enough to possess them may be considered too old to get a foot in the door. Many competitions, for example, are open only to those in their early 30's or younger.

"A lot of teachers don't understand that big voices don't settle until 35," said Speight Jenkins, the general manager of the Seattle Opera, which has a reputation in the opera world as a haven for large-scale voices. "Voice teachers in general do not encourage the unique, the original voice." Instead, he said, they encourage "the voice that can hit all the notes and do what is supposed to be done," but without any particular flair, artistry or distinction.

But voice teachers are not solely to blame. Young singers, too, are impatient, and in our "American Idol" culture, quick fame is more appealing than slow maturation. What's more, the vaunted apprentice programs tend to look for singers they can actually use, in small roles, rather than simply train.

However these factors are combined, the result is a preponderance of light, agile voices in young, attractive bodies. They may be pretty to listen to -- and certainly to look at -- but they are not ultimately as interesting as bigger, more mature voices. Nor do they have the same staying power. Plenty of young American singers have sprung onto the scene only to fizzle within a few years.

"I worry that today many of the people judging singers judge on accomplishment as opposed to talent," said Stephen Lord, the music director of the Opera Theater of St. Louis and the Boston Lyric Opera, known for his careful work with young artists. "If someone walks in and can sing every note of 'Marten aller Arten,' " -- a virtuosic soprano aria from Mozart's "Abduction From the Seraglio" -- "this is seen as the next coming, as opposed to someone young, struggling with physiology, but with more talent. What you see in front of you isn't really the person with the potential for the biggest career."