Voice coach JOAN LADER

When Madonna needed to beef up her voice for the title role in the film Evita, she went straight to the vocal coach of Patti LuPone, who originated the part on Broadway: Joan Lader, a hallowed figure in the singing world. Although Lader’s students have reportedly included pop and jazz stars like Roberta Flack and Dianne Reeves (the teacher is tactfully mum about her clients), she is perhaps most popular in the theater community, where nearly every top performer seems to be on her roster. In addition to coaching, Lader assists singers on an emergency basis; the heavy amplification of Broadway sound design, she says, can overwhelm the unwary vocalist. “They can’t always hear themselves, so there’s a tremendous danger of oversinging,” she notes. “The biggest thing that I can do for them is to tell them, 'This is your margin of safety; this is how far you can go without getting hurt.’ ”

Lader, 59, has a master’s degree in speech pathology and refers her clients for endoscopic imaging to study them from the inside out. (“What are the adjustments they have to make? Does it have to do with their larynx? Or their tongue?”) But such high-tech methods are only part of her appeal. “She has amazing exercises for relaxation and breathing,” says Tonya Pinkins (Caroline, or Change). “She has a gift—she can hear a sound and know what the body is doing to make it.” And her hard work in the studio, Lader says, pays off when her clients’ voices ring out not just gloriously, but responsibly: “It’s exciting to be able to just listen to the music and not worry.”—Adam Feldman