Notwithstanding the recent efforts of brass, woodwind, string and percussion players to demonstrate the a cappela potential of their respective instruments, the piano still wins hands down as the medium of the soloist's art. Five recent discs of jazz piano -- one of them with unobtrusive bass and drums, the others unaccompanied -- corroborate the ascendancy of the keyboard.

Jimmy Rowles has ridden the jazz circuits for four decades playing with score upon score of the greats including Billie Holiday, Benny Goodman, Lester Young and Charles Parker. But it is only in the 70's that he has come into his own on record as a soloist. His trio album with bassist George Mraz and drummer Leroy Williams (both of whom are here very laid back), "We Could Make Such Beautiful Music" (Xanadu 157), is his best yet.

Rowles' "Stars and Stripes Forever," an unlikely vehicle for improvisation, utilizes everything from boppish trumpet lines to crashing orchestral effects and a coda of "Taps," all of it driven by a bouncy bossa beat. It's worth the price of the album. A blues-tinged "Shake It But Don't Break It" recalls the cross rhythms and percussive touch of its composer, Erroll Garner, and "I Can't Get Started" is a beautifully ambling bit of intimacy.

Dave McKenna refers to himself as a barroom pianist. That's the scene he's found himself in for some years but he's also done stints with Woody Herman, Gene Krupa and Bobby Hackett. It takes a strong left hand to rumble the blues and boogie-woogie; McKenna provides awesome proof that he is a master of both idioms on his own "Dave's Blues" in his new album "Giant Strides" (Concord 99). But that's not the only place he comes from, as he clarifies on Charlie Parker's "Yardbird Suite," which contrasts a spare, single-note right hand with a busy, infectiously swinging left. "If Dreams Come True" is one of several numbers that justify the album's title, for McKenna has a long reach, both on the keys and over the years.

The Detroit area has nurtured some fine jazz pianists, among them Hank Jones, Barry Harris and Tommy Flanagan. Less well known but very deserving of attention is Sir Roland Hanna. He devotes "A Gift From The Magi" (West 54 WLW 8003) to his own compositions with one exception. Hanna, whose cultural roots include the blues-drenched sounds of the Sanctified Church, is also steeped in the 20th-century European musical tradition, especially Bartok and Debussy. "A Romp Through the Woods Somewhere" contrasts four-handed overdubbed passages with nearly equally dense solo stretches. The album's title piece builds from a placid opening to a stomping, arpeggiated amalgam of lyricism and the blues. "A View From the Island" is rich in musical water images. Charlie Haden's "Silence" is a study in distillation.

Jay McShann has long been identified with the blues and not surprisingly so, considering where he cut his musical teeth. "Kansas City Hustle" (Sackville 3021), whose title commemorates his provenance, displays a versatility and sophistication that belies his putative backroom limitations. Readings of Ellington, Monk and Hoagy Carmichael show off his abilities as a well-rounded jazz pianist. His roots in the blues do indeed come to the fore on Ivory Joe Hunter's "I Almost Lost My Mind," and on several originals including "Blue Turbulence" (aptly named) and the title cut which walks the boogie at a brisk clip.

Mary lou Williams was long ago dubbed "the first lady of jazz." From her big band arrangements for Andy Kirk, Ellington, Goodman, and others in the '30s and '40s through her small combo and solo role and later large-scale religious compositions to her 1977 collaboration with avant-gardist Cecil Taylor, she has demonstrated a versatility and ecelecticism that has drawn sustenance from the roots and yet always remained modern.

A six-part summary of her origins on "Solo Recital: Montreux Jazz Festival 1978" (Pablo 2308 218) is a virtual seminar in gospel, ragtime, blues and swing. An early piece of her writing, "What's Your Story Morning Glory," is ruminative and haunting. She offers a fresh re-wording of the oft-played Gershwin ballad "The Man I Love" and closes out the concert with a striding "Honeysuckle Rose."

For, say, a saxophonist, trombonist or drummer to perform alone is clearly a feat. We're perhaps not so surprised at the agility, technical prowess, even sheer audacity of it as that -- to borrow a famous phrase from Dr. Samuel Johnson, "like a dog's walking on its hind legs" -- they're able to bring it off at all. But solo jazz piano, when it is good, obeys the dicta of Jelly Roll Morton and Art Tatum; imitate an orchestra and have a whole rhythm section in the left hand. None of the five pianists reviewed here falls short in either respect.