Big names needed - but where do you find them?

A women's jazz festival carries with it a built-in problem - there just aren't a lot of big-name women in jazz, and this kind of festival needs big names to sell out its concert halls.

This year, as both reviewer and participant, I was able to get a double perspective of a one-of-a-kind event in this category: the Kansas City Women's Jazz Festival, in its sixth year.

Behind the scenes, I saw marvelously enthusiastic musicians from all over (mostly female), putting everything they had into playing at the various jam sessions and preparing for the festival concerts. Out front I saw an event which , for all its initial promise, seems, sadly, to be in some trouble.

The problem certainly does not lie in the quality of the talent that was presented - pianists Tommy Flanagan and Marian McPartland, vocalist Sheila Jordan and her bassist, Harvie Swartz, and vocalist Anita O'Day all put in fine performances. They were joined by the combo contest winners - an exceptionally gifted group from Rochester, N.Y., called Joy Spring, and by the All-Stars, a sextet in which I played piano.

The very popular quintet Alive! came back for its third appearance, and Gene Aitken, a jazz choir director, brought his group from the University of Northern Colorado for an excellent set in the final concert. In addition, there were vintage films featuring jazz women, presented by Leonard Feather, and a series of workshops for instrumentalists and vocalists.

No - the problem seems to be in a less tangible area. There's a feeling that the festival is running out of steam.

This year there was no big headliner. Anita O'Day may well be one of the finest, if not the finest, jazz vocalist alive, but unfortunately her name doesn't have the draw of, say, an Ella Fitzgerald or a Sarah Vaughan. If the festival is to continue, it seems imperative that its artistic directors find some way to include one or the other of these very popular and very expensive jazz women.

The alternative is to start repeating headliners of previous years - Carmen McRae, Toshiko Akiyoshi/Lew Tabackin Big Band, Cleo Laine, Joanne Brackeen, Marian McPartland, etc.

Founders Carol Comer and Dianne Gregg have said over and over in interviews that they welcome the day when the festival will no longer be the Kansas City Women's Jazz Festival, but simply, the Kansas City Jazz Festival. Part of the ''running out of steam'' feeling, I think, comes from the fact that the festival is having growing pains - the little knots of militant feminists that reared their heads in the first couple of years seem to have disappeared, and nobody seems to care any more about political issues - they just want to play. And yet the festival policies haven't changed.

A case in point - on one day, two long jam sessions were run simultaneously - one just for women (no men allowed), the other a ''mixed'' session. The women's jam was held in a large ballroom at the Radisson Muehlebach Hotel, which seats over 1,000 people. The sound equipment for this session was poor, and the quality of some of the music wasn't much better because of a lack of strong rhythm sections. Despite the presence of a few fine women bassists and drummers (with a special nod to the indefatigable bassist Joan Griffith, who has played an impossible number of hours every year since the festival began), there just aren't enough good ones to sustain a nine-hour jam session.

Conversely, the mixed session was held in a small, intimate room, and everyone was invited to play. Result: People thronged the mixed session, and many just couldn't get in - they stood around in the hallway, complaining. Ironically, there was plenty of opportunity upstairs in the ballroom for men to sit in, but they weren't allowed.

True, this move for a segregated session was originally justified by the unrest of some feminist groups, but since that furor has died down, it seems wise to drop the outgrown policy at the jams.

Overall, the idea of a festival mainly for women still seems valid, since it helps to bring many heretofore unknown women jazz musicians into the public eye. One of these deserves a special mention: Nadine Jansen, from Scottsdale, Ariz., who has had a long but relatively unheralded career as pianist, singer, and trumpeter/flugelhornist. She was invited to be a member of the All-Stars, and brought down the house with her touching rendition of ''I Thought About You,'' which she sang, accompanying herself at the piano, and then played on the flugelhorn, also accompanying herself at the piano! Everyone present was deeply moved by this very special lady, whose performance went way beyond the realm of novelty.

Thanks to this festival, a lot more people know not only about Nadine, but about many other excellent but little-known players who have appeared over the past six years. One can only hope, for the good that it does, that the Women's Jazz Festival will not only keep going, but that it will continue to broaden its scope.