During her brief fling at fame, Janis Joplin would often reach her hands out to the crowd pressing toward the stage. With powerful lungs, she would wail: "Go ahead and take it; take another piece of my heart!" And there it was -- her heart, her sex, herself -- emptied out in an overwhelming cry for everyone to take from.

With her hugh voice, Joplin shattered the image of the demure white woman. She emptied out the blues and lust most women had kept hidden. In a way, she posed the questions that led to feminism, though she never came up with the answers. Her great voice could reveal everything she felt but couldn't transform those feelings.

The premature death of Janis Joplin robbed us of a great voice. Ever since, other women have tried to fill that role. The newest pretender to the throne is Mary Burns. "Mary Burns" (MCA 5122), the debut album of this St. Louis singer, contains a Xerox copy of Joplin's "Move Over." Duplicating Joplin's sound, however, is not the same as duplicating her impact.

Burns is a fine singer. She can grind her voice into gravelly anguish or smooth it out into husky intimacy. No matter how she stretches her voice, though, it all sounds like an entertainer's bag of tricks. She never brings any new insights to the 10 tunes she covers. Nothing that was hidden is emptied out.

Kim Carnes has a grainy voice that makes her sound like a female Rod Stewart. Like Stewart, Carnes adjusts the grain to give certain lines a bluesy accent and others a fluid send-off. Her fifth album, "Romance Dance" (EMI America SW 17030), is bright poprock in the Linda Ronstadt mold, quite unlike Carnes' work with country schmaltzer Kenny Rogers.

Six of the record's nine cuts are written by Carnes alone or with her husband, Dave Ellingson. Some of the originals are charming, but the two oldies stand out. They have the tempo and hooks for Carnes to test herself. Like Ronstadt, Carnes plays it safe. Unlike Joplin, she never pulls a song apart to discover something new.

One of the few singers taking Joplin's kind of chances today is Tracy Nelson. Nelson has an enormous voice, a contralto that swells up from understated versed into overwhelming climactic choruses. Like Joplin, Nelson brings every feeling inside her out through the voice.

The personality that's revealed, though, is much different in each case. Nelson is a tough, confident survivor, much different from Joplin's victim-on-the-brink. When Nelson sings the blues, it's more likely to come out as "It's not losing you that's got me down so low/I just can't find another man to take your place," than as "Take another piece of my heart."

Nelson has two new albums out. "Come See About Me" (Flying Fish FF 209) is a collection of 10 rhythm & blues tunes that Nelson has always wanted to do but never got around to. "Doin' It My Way" (Adelphi AD 4119) contains eight tunes that she's recorded before but always wanted to redo "my way."

On the R & B album, Nelson jumps on the best with her own tough brand of sexuality. She changes the Supremes' "Come See About Me" from a plea into a challenge. On Ann Peebles' "Walk Away," Nelson's departure sounds more like a swagger than a retreat.

"Doin' It My Way" may be Tracy Nelson's best record ever. All eight songs are excellent vehicles and Nelson drives them with the full control she lacked on the earlier versions. Her voice sounds as if all its restraints had been lifted and it can soar wherever it wants.

She belts out "Lies" as if she were throwing the facts in an old boyfriend's face. She savors "Time on My Side" with the satisfaction of one who can afford to wait. Her own "I Could Have Been Your Best Friend" is tinged with regret about the man who couldn't understand the difference betwen romance and friendship.

One of the greatest mysteries of pop music is why Tracy Nelson never became a bigger star. Now she is recording the best music of her life on small independent labels. Anyone looking for Janis Joplin's legacy today ought to look in Nelson's direction.