Due to circumstances beyond my control and a set of directions straight out of that old folk song "Charlie on the MTA," I missed the first half of Joni Mitchell's program at Forest Hills Tennis Stadium on Saturday, in which The Persuasions performed songs from their new Flying Fish album.

A five-man vocal group devoted exclusively to the nearly lost art of a capella singing, The Persuasions have been performing together for 15 years. They are still capable of pulling of surprises in the studio and on stage. I was present at one of their Flying Fish recording sessions at the Electric Ladyland studios, so I know their new stuff packs a wallop that must have wowed the crowd.

No slouch at livening up her concert dates by the inclusion of consummate musicians, Ms. Mitchell made a wise choice of The Persuasions as her opening act. Although they are in no way a novelty act per se, many of the young people present probably had little, if any, prior exposure to such as The Persuasions' purity of musical form combined with streetcorner harmonies and humor.

An untitled song about justice and blindness and a lighthearted "Why Do Fools Fall In Love" encore Ms. Mitchell sang with The Persuasions worked amazingly well. She was neither folk, rock, or soul, but by simply being herself and having a fun time adding her reedy vibrato and vocal energy to The Persuasions' perfectly pitched singing, she created a brand new musical experience. Ms. Mitchell is utilizing The Persuasions on several venues during the current tour. I'd like to see an album of this terrific combination!

On one of the Mitchell-Persuasions encores, they were backed by keyboardist Lyle Mays on either a real organ, or a synthesizer that sounded like one. (From stage left where we were sitting in the backless bleachers behind the monitors, we couldn't see most of the instruments, although the sound was first rate, beautifully mixed.) The Persuasions do not work with musical backing, but the "organ" provided an ideal churchy touch for the Persuasions-Mitchell blend.

A Tribute To Mingus

Joni Mitchell's enterprising new Asylum album, Mingus, is a tribute to the late bass player and band leader who died earlier this year of amyotropic lateral sclerosis, the muscular disease that also killed Lou Gehrig. The album is an experimental collaboration between Ms. Mitchell and Charles Mingus. It contains six long tunes, four with music written by Mingus, and two total Mitchells. The rest of the album is bits and pieces of tape-recorded Mingus "raps."

The "raps" are fitfully amusing: more interesting if you were acquainted with Mingus and some of the matters that occupied his concern. The music, however, has many really masterful moments, and some well executed passages, both vocal and instrumental.

In terms of the concert, by far the most popular song from Mingus was "God Must Be A Boogie Man," which Ms. Mitchell based on the first four pages of Mingus' preachy but often funny autobiography, "Beneath The Underdog." "Mingus 102," Joni called it. In no way is this a jive number; it is mean (sic) to be serious, yet salty at the same time, the way Mingus was when he wanted to be heard. (Remember "Fables of Faubus"?)

Kids were repeating "God must be a boogie man!" as they left the bleachers and even 20 minutes later, I heard it on the subway! Although "Woodstock" was the last song of the evening, and the anniversary of that event was on people's minds, as were Ms. Mitchell's lyrics, "Boogie Man" is so musically infectious it wouldn't go away.

Several other compositions from Mingus were performed, and these were the selections on which Ms. Mitchell's all-star jack-rock band went to town and let their special lights shine. Her players were Pat "New Chautauqua" Metheney on electric guitar, Jaco Pastorius (who also played on Ms. Mitchell's Hejira LP) on bass, Lyle Mays on keyboards, Michael Brecker on reeds, and Don Alias on drums and percussion.

The instrumental grouping most often used was drums, piano, guitar and bass, but there were unusual instrumental pairings, and numerous special effects such as the use of an Echoplex and some minute-and-a-half tape loop repeats.

The arrangements and pacing were well organized, as were the selection of tunes in sequence. Ms. Mitchell introduced songs known and not yet known and there was a nice flow of music. She looked lovely in a black printed silk jersey pants suits, and danced in place when so moved.

She performed many audience favorites: "Big Yellow Taxi," "Coyote," "Dreamland," "Furry (Lewis) Sings the Blues," and her biggest hit, "Raised on Robbery." "Robbery" was sung with full band backing, just before she left the stage for the first time.

Ms. Mitchell has come a long way since her beginnings as a folk singer, and her voice has matured considerably, along with her added control. She's not yet a complete jazz singer, but she is a more than competent singer of jazz, able to scat-sing with ease and obvious pleasure. Whatever elements of pretension there might unintentionally have been underlying the Mingus album, Joni displayed an honesty and vocal technique beyond my own expectations. I was impressed with her presentation and delivery, and with the entire concert. It was a magical evening.