Blow that horn, sister! (Divalution).

Who is Valaida now and why don't I know about her? I'm asking myself those questions after hearing an excerpt of a radio documentary about Snow, who, in her heyday, was known as "The Queen of the Trumpet" and who even Louis Armstrong called the "second best" trumpeter in the world.

I pride myself on having a pretty good knowledge of jazz history and knowing the names of notable female artists of the genre. So how can it be that I don't know the name of someone who was commended by the greatest figure in the annals of jazz music?

The history of women in jazz--as in many other art forms--is largely unknown, forgotten, or dismissed. Jazz history is unique, however, because it has its share of female icons: Billie, Ella, and Sarah, to name three. But drop the divas from the list, and brain lock sets in. How many music fans can name more than one or two female jazz instrumentalists, composers, or arrangers?

"Jazz is one of the last art forms to recognize the significance of feminism," Angela Davis, professor of history of consciousness at the University of California, Santa Cruz, tells me during a recent phone interview. "It's still very much a masculine project. Jazz women are still considered the exception, and gender segregation is still very much a part of jazz. I think this is significant, particularly since jazz is considered the quintessential American music. It's sort of considered to be the democratic music of America."

In March, Davis, the former Black Panther turned radical academic, led a panel discussion on "Women and Jazz" as part of this year's San Francisco Jazz Spring Season. The festival's artistic director, Joshua Redman, featured a week-long celebration entitled "Jazz Women," which served up a variety of intriguing performances and events in honor of Women's History Month.

One event offered a cinematic tribute entitled "The History of Jazz Women on Film," an evening featuring classic clips of under-recognized greats like electric guitarist Mary Osborne and saxophonist Vi Redd.

Another program featured pianist and former Anthony Braxton Quartet member Marilyn Crispell and her trio, sharing the bill with "free jazz" drummer and composer Susie Ibarra and her quartet. Down Beat magazine called Ibarra "one of the best and brightest drummers to come out of New York (or anywhere) in the last few years."

People often think that" `free jazz' or `free anything' is loud noise or coming from anger," Ibarra told The New York Times back in 1999. "But the music I play has emerged from forty years of studied development, certainly in terms of drum conception. True `freedom' can only come from discipline."

The celebration also included high-energy performances by Cuban music specialist Jane Bunnett and her band, Spirits of Havana, as well as a saxophone showcase featuring the lyrically dynamic Jane Ira Bloom Quartet.

"I thought it was really important to include women in this celebration who are not singers," Redman explains to me. "Not because singing isn't a totally important part of jazz, but because there are a lot of women working in other areas--composing, arranging, and as instrumentalists--who don't get the attention they deserve."

In the past, women who decided to pursue careers in jazz as anything other than vocalists were generally viewed as oddities. But that didn't deter those women who were courageous, talented, and determined to find a place on the bandstand.

I started sniffing around on the Web to find out more about these little-known jazz legends, including Snow. I learned that she became a professional performer (dancer, vocalist, and trumpeter) at age fifteen, and before long was opening on Broadway in Eubie Blake's show The Chocolate Dandies in 1932. She toured in both the United States and Europe, appeared in several Hollywood films, and started her own all-woman band. At the height of her fame in the late 1930s, she traveled around in her orchid-colored limousine and was courted by international celebrities like Maurice Chevalier and Earl "Fatha" Hines. Unfortunately, Snow was performing in Denmark in 1940 when German troops invaded, and she was arrested and held in a prisoner of war camp for eighteen months. Some say that Snow's imprisonment by the Nazis was the reason her fame waned. Others say that it was due to the same sexism and racism she faced during her life and career in the United States--factors that forced her to go to Europe in the first place.

Snow wasn't alone during those early days of female jazz musicians. Along with Redd and Osborne, instrumentalists like pianist Mary Lou Williams, trombonist Melba Liston, and even big bands like the International Sweethearts of Rhythm paved the way for later female mavericks like flutist Bobbi Humphrey and percussionist Terri Lyn Carrington. Altogether, they managed to carve out a niche that defied the once-common view that the only successful jazz women were vocalists.

"Women have played jazz on every instrument, in every style and era of the music's history, and have contributed to, and engaged, the same aesthetic and technical developments as their male colleagues," writes Sherrie Tucker, assistant professor of women's studies at Hobart and William Smith Colleges and author of Swing Shift: `All-Girl' Bands of the 1940s (Duke University Press, 2001). "Yet--with the exception of singers and some pianists--they are invariably perceived as new. Once received as novelties, now more often celebrated as examples of women's progress in society, female jazz musicians are discovered and erased in one fell swoop; marketed as incipient, consumed as curiosities. Yet, despite their aura as perpetually unprecedented, female jazz musicians do have a history."

Angela Davis says that part of the problem for women in jazz is what she terms the "gendering of instruments."

"We can come up with a name of Mary Lou Williams, but we don't necessarily think about [trombonist and arranger] Melba Liston," says Davis. "The drum is still considered very much a masculine instrument. Terri Lyn Carrington, who has been playing the drums for years, started off as a very young child, performing with greats like Dizzy Gillespie. People still characterize her as playing like a man."

Not everyone, not even every woman, would agree with Davis's take on things. One of the artists featured during the week-long SFJAZZ celebration was Maria Schneider, the composer, arranger, and big band conductor whose album Allegresse was chosen as one of Time magazine's top ten of 2000. Schneider doesn't think of herself as a pioneer for women in music, and she doesn't feel a special obligation to promote women musicians.

"My composing is something I love to do. I love to write," she explains. "I remember some man heard my band once and said, `I hear that you're going to start trying to hire more women in your band,' and I thought, why would I do that? If I hear somebody who plays great and there's a spot in my band that's open and it's a woman, fine, and if it's not, fine." Steam can almost be heard coming out of Schneider's ears at this point. "If anybody helped me because I was a girl coming up, too bad for them. I thought they were helping me because they believed in my potential as an artist. But I just want to be judged on my music, not with this qualifier of being a woman."

Schneider, however, does agree that perhaps there is something innately "feminine" in her work. "I don't dispute the fact that women have a different perspective on life that gets brought into art," she says. "I do think there's something female that comes through my music."

While nonvocalists dominated the SFJAZZ celebration of women in jazz, the week would not have felt complete without some stellar vocal representation. Cassandra Wilson, the woman whom Time called "the most heralded jazz singer of her generation," brought her luminescent voice and energy to the audience gathered at San Francisco's Masonic Auditorium and demonstrated why she is aptly deserving of that title. The evening was the opening performance of the tour for Wilson's new album, Belly of the Sun. But Wilson seemed to be feeling no pressure as she coolly sauntered onstage in bare feet' and flowing lounge wear and offered up a memorable evening of song styles. Wilson would take up a Dylan tune one minute, move deftly to an original composition next, and then spin your head around with an utterly surprising interpretation of something like the former Glenn Campbell hit "Wichita Lineman."

Wilson's performance, one of the last in a week-long series of memorable events, didn't steal the spotlight away from female instrumentalists, but rather firmly accentuated the notion that sisters are doing it for themselves in all areas of jazz.

Andrea Lewis is a San Francisco-based writer and co-host of "The Morning Show" on KPFA Radio in Berkeley.