EVERYTHING ABOUT her was a complete picture of grace - her voice, her guitar and piano playing and her stage presence.

Joni Mitchell, folk-rock female vocalist performed before a crowded hillside audience Tuesday night at the Mississippi River Festival on the Southern Illinois University campus at Edwardsville.

Miss Mitchell captured the crowd from the first note she sang, and by the evenings' end, had the audience feeling as though they were sitting in her living room listening to the music she has created.

The singer-songwriter was probably first known as a lone performer who sang songs about seagulls, lifestyles and lovers. She was classified by many in the same category as Joan Baez, Judy Collins and other female folk singers whose music included nothing but themselves - no backup groups.

She has several albums out and has gained fame from songs such as "Yellow Taxi" which tells of paving paradise and putting up a parking lot, "Woodstock" which she wrote about the first large rock concert in Woodstock, N.Y., and "You Turn Me On, On the Radio" about a lover.

Currently, Miss Mitchell has two songs on the top ten, "Help Me" and "A Free Man in Paris." Not only does she record nearly all of her own songs, but other artists including Crosby, Stills, Nash and Young and Judy Collins have recorded music she has written.

Tuesday night began on the wrong foot with a power outage on the SIU campus. An announcer came out and announced to the crowd that it would be nearly two hours before all power would be regained. Until then, reserved power would be used which meant that some lighting was off as well as some speakers.

Some disapproving sounds were heard from the audience, but once Miss Mitchell made her first step on the stage no one seemed to care any longer.

She sang her first song with much ease as if she had just stepped into a room full of friends and decided to share her talent with them. The crowd greeted her too, as if they were friends.

MISS MITCHELL sang about five songs non-stop without saying a word - but there was no need, as her songs said everything and anything that she needed or wanted to say. She then took an intermission.

The first half of the concert might have been quite a shock to many Mitchell fans who have not followed her in the past year or two.

At one time, Miss Mitchell's concerts consisted of only herself, her guitar, piano and any other instrument she played. But Tuesday night she had some friends walk out on stage with her.

The Joni Mitchell of today is not the lamenting, mellow female vocalist who sang her sad songs alone on the stage. She now has an entire back-up group consisting of electric guitars, bass guitar, drums and every now and then a woodwind instrument.

Her newer songs like "Help Me" and "A Free Man In Paris" are taking on a new sound with a little more rock tempo and a lot of jazz tempo.

Many loyal fans have been turned off by this new style, left wondering where the old mellow Joni Mitchell is. But what this new style shows is that Miss Mitchell is not only a superb lyricist, but a versatile music writer as well.

Her newer songs have a unique quality that only Miss Mitchell could achieve. She does not restrict herself to holding her guitar all the time. A few of the songs she simply stood at the microphone and sang her heart out.

During the second half of the concert, Miss Mitchell returned to the stage appearing as the "old" Joni Mitchell while her group took a break. She sang many of her songs off the "Blue" album and took the crowd back in time to the very beginnings of Mitchell music.

She also began to talk to the crowd. After sparse shouts of "I love you, Joni," she said, "Wow...it is so hard to respond to you people when you say things like that. It is really beautiful, but gosh...it is so dark out there. I don't even know you." Then she giggles.

THAT GIGGLE kept coming back from time to time. It reminded one of "a little girl giggle" and certainly did not look like it belonged to this graceful lady. But it only adds to what Joni Mitchell was on stage. She was feminine but she was human and obviously enjoyed herself and what she was doing.

But she had her moments too when the eyelids were shut and she seemed completely oblivious to anyone. Her eyebrows would furrow and then it was Joni and ONLY Joni on that stage digging from a part of her life that she saved in song.

Though Miss Mitchell was proving her genius in music and proving her genius as a vocalist, she did perform a little too long. She could have ended her concert about four songs before she did. The night was getting chilly for those sitting on the grass and due to a late start because of the power outage it was getting late.

But there were probably many fans in the crowd who were oblivious to time and temperature and were only aware of this graceful lady and the music that she was sharing.