AS GOOD AS their records are, the Roches have proven time and again that their true strength and appeal is in their live performances, where the eccentric beauty of their voices -- and their quirky wit and warmth -- radiate around. Saturday's concert at Lisner may be the optimal way to experience the songs on their fourth album, "Another World."

On first listen, it sounds dismayingly like the three sisters from deepest New Jersey have caved in to radio ga-ga -- they've dropped their pristine, folk verite sound and added the chirping synths, chattering drum machines and jagged guitar that are requisites for "hit records."

But before crying "sellout!" Roches cultists should listen a few more times. These 10 songs, which approach aging from various angles, may not surpass previous Roches heights, but they're still topflight by any other pop-music measure. And though the sorority harmonies are homogenized into an anonymous girl-group sameness, their unmistakable individual voices make the superfluous sonic overlays vanish as the record becomes familiar.

It opens with a stunning trio of songs: the ethereal, prismatic melody of "Love Radiates Around," followed by the jauntily cynical "Another World," and Maggie's hushed homage to the Fleetwoods' 1959 "Come Softly to Me." Other nuggets include Suzzy's sweetly resigned "Love to See You," and "Weeded Out," a plaintive ode to betrayed farmers. (Who forgot to invite ng Jennie Mae, impatient with her family and schoolmates, shares her grandmother's alertness and is determined not to let impending adulthood impede her imagination. As she says, "I'll bet when the first fish walked out of water all the other fish beat the s

Driver adds some darker notes to the proceedings. Jennie Mae's mother Lettie is down in the dumps over her loveless Punch-and-Judy marriage to Earl, a boorish trucker who wants to sell Gramma's land so he can buy a new rig. Driver leavens this soapy stuff, which makes the first act somewhat pokey, with passels of authentic-sounding rural wit. But he compresses too much into the play's last moments, adding a macabre, even nasty twist, but not enough reaction from the characters.

Three winning performances ease the play over its soft spots. Eighty-one-year-old Katherine Squires finds the right combination of sugar and ginger for Gramma Rinn. And Jennie Mae earns another gold star for Erika Bogren, who expertly colors her lines with adolescent excitement, impatience and yearning. Seven-year-old Chad Brian Wain has a thweet lithp and a precocious professionalism as Earl's son Lyle, who lives mouselike under the porch, absorbing grownup talk.

Lynnie Raybuck is able as careworn Lettie, who, with Grandma Rinn's help, discovers that a creative flame still burns in her. But the role of Earl seems an afterthought, and is played as such by Beau James. Russell Metheney's set, an appropriately homely, cluttered farmhouse, looks as though it has seen generations of frustrations.

A WALK OUT OF WATER -- At Studio Theater through December 22.