"Starbright, starbright, You got the lovin' that I like, all right, Turn this crazy bird around, I shouldn't have got on this flight tonight."

When Joni Mitchell wrote that typically wistful lyric about three years ago, she unwittingly produced a fairly accurate capsule-review of her concert-to-be at Blossom Music Center Tuesday night.

Not that it proved a disastrous flight - far from it. Any musical excursion into the unique poetic imagination of Ms. Mitchell is bound to be interesting. But simply interesting an audience is not synonymous with entertaining it, and this the willowy towhead from Canada was not consistently able to do. Call it a depressingly ordinary flight.

IT MAY HAVE BEEN symptomatic that, early in the second half of Joni's set, a boisterous young heckler interrupted what no doubt seemed to him a long and pointless anecdote to shout for some boogie.

Ms. Mitchell, who obviously had been into her own private little cosmic trip - she was telling her 17,000 admirers all about the crazy party she once attended where the walls and floors were mirrors, the food was white and the furniture transparent - was visibly shaken by the remark, and she blurted out something to the effect of "C'mon, man, you're really gonna spoil the show for everyone - the boogie comes later."

Well, the boogie never DID come later, or if it did, it came past this reporter's deadline. And Ms. Mitchell, who appeared tired and vocally below par before the interruption, never picked up the thread of her story - or regained the rapport she was beginning to establish with the crowd.

It was apparent that Joni Mitchell, whose art thrives on intimacy was simply not comfortable playing for such a huge crowd. Better they had booked her into a coffeehouse with just her guitar, her piano and 30 quietly contented fellow travelers. Her cool, introspective, worldly-wise songs lose much of their poignance and charm in the wide open spaces.

JONI'S SONGS also happen to be rather fragile in mood and expression - and to saddle them with a loud, graceless back-up band like Tom Scott's L.A. Express is a bit like trying to recite a haiku in the middle of Grand Central Station.

As exponents of your average mid-'60s jazz sound, this five-man group just about passes muster. Should Scott and his buddies ever decide to throw away about 1,999 of their 2,000 amplifiers, you might even discover there is some modest invention to their music. But the Express adds nothing to Ms. Mitchell's music but decibels, a solid rhythmic foundation, decibels, aural mucilage, and more decibels.

Only out on the lawn - where your shell-shocked scribe eventually retired - could you understand what her lyrics were about or hear the singer's voice in reasonable balance with the back-up group - instead of blasting unnaturally through an instrumental din.

I'm told this is the same L.A. Express that sounds superb on Joni's new "Court and Spark" album and that wowed the faithful when Ms. Mitchell played Cleveland a few months ago. Either the band should have brought its recording producer to Blossom, or turned the stage entirely over to Joni, who proved during much of the second half that she can get by without a lot of help from her friends.

TRYING HER BEST to ignore the steady parade of flashbulb-popping fans who scampered up and down the aisles throughout her set, the singer served up a lot of material from recent albums while overlooking many of the hits with which she is identified. All these she delivered in her reedy, plaintive voice, complete with the usual Mitchell vocal trademarks (the register breaks, the wobble, swallowed syllables), which are fast becoming mannerisms.

Occasionally there were glimmers of the subtle Mitchell magnetism which comes through so hauntingly on her albums. As always, "All I Want" tapped directly the deep well of ambivalent feelings which hold two people together - and truth gushed forth. "Put Up a Parking Lot" had a certain funky swagger.

But it wasn't enough. The chemistry which should have happened between Joni Mitchell and her audience, didn't. Hopefully, when she returns to the Summer home of the Cleveland Orchestra in the future, she will have gotten her act better together, made a more earnest effort to establish some sort of rapport with the fans - and discarded those internal amplifiers.