Alberta Hunter - the lady sang more than the blues

''Trouble and dark days just can't last always,'' Alberta Hunter used to sing in one of the blues she composed herself. Sing? She practically shouted the words, with the exuberance that makes a blues singer seem less a victim than a primal force.

Like all the best blues singers, from Bessie Smith on, Alberta Hunter also sang of two-timing men with their low-down ways, and the fickleness of human nature in general. ''Nobody knows you when you're down and out,'' goes one of the most famous and most sobering of blues she favored. ''In your pocket not one penny, and your friends - you haven't any.''

But even when she was singing the bluest blues, Alberta, a small, deceptively fragile woman, vibrated with life, clapping her hands as if she were singing gospel songs - bringing the good news.

''I'm livin' my life while I'm livin' '' - these Alberta Hunter lyrics could stand as the motto for her life, and she belted out the words to her audiences until her 90th year.

Of all the blues singers, Alberta Hunter may have been the most versatile. She sang musical comedy, too, appearing in a London production of ''Show Boat'' 56 years ago with Paul Robeson. She also performed as that '20s invention, the chanteuse, singing in French, Italian, and German - as well as Yiddish.

Finally she extended her zest for ''livin' my life while I'm livin' '' beyond music. In the '50s this woman who, from 1921 on, recorded with everybody from Louis Armstrong to Fats Waller, from Fletcher Henderson to Sidney Bechet, enrolled in a nursing program at the Harlem YWCA. For 20 years she worked as a scrub nurse at Goldwater Memorial Hospital on Roosevelt Island, never missing a day.

As a singer, she had a voice like a brass section and a heart twice as big. She put that heart into her nursing, just as she put it into singing her ''Downhearted Blues'' - a performance that left her listeners anything but downhearted or blue.

The blues begin at the roots, with an earthy vitality. But anybody who took Alberta Hunter to be just a ''salty mamma'' misread her songs and her life. The driving beat, the lyrics that laugh until they cry (and vice versa) reach out to celebrate more than good-time partying. The singer who didn't just chance to be a nurse was, in her own ebullient way, a consoler and a nurturer.

This second role became even more apparent when Alberta - forced into mandatory retirement as a nurse - returned to her first career as a singer, becoming somewhat of a television celebrity and reaching a wider audience in her 80s than she ever had before.

''I gotta mind to ramble,'' she sang with undiminished zest, and audiences with an old-fashioned need for high energy and a new taste for strong women responded.

The same week that recorded Alberta Hunter's passing declared August Wilson's new play about another blues singer, ''Ma Rainey's Black Bottom,'' to be a ''genuine work of art'' as well as the season's ''first smash hit.'' The same day her obituary ran, a Broadway production of ''Mr. Jelly Lord'' - based on the life and music of Jelly Roll Morton - was promised for the spring. Suddenly Alberta Hunter's trade is busting out all over.

The blues haven't changed. We have. Behind the obligatory despair and the minor key, we can now feel a voracious love for life.

Like all blues singers, Alberta Hunter interspersed little asides to the audience. ''Talk to me! Talk to me!'' she would cry, keeping a perfect beat. Or when that evening sun went down and the going got really heavy, she would shout: ''Help me! Somebody help me!'' But after all the good moaning was done, one word used to burst out of her like a trumpet: ''Hallelujah!''

Could an oratorio singer say more?