Mellow-voiced Joni Mitchell staked a lyrical claim on the affections of about 4,100 fans last night at The Auditorium and struck gold.

The Canadian-born songstress got off to a pleasant enough start, but didn't really begin to move the near-capacity audience until her third number, "Free Man in Paris."

Accompanying herself on acoustic guitar and backed by a quintet called the LA Express, Miss Mitchell's enchanting tones came across with a clarity and power that immobilized the once restless crowd.

From there, she built up to a rousing rendition of "Woodstock" which had the audience on its feet in gratitude at the end.

Miss Mitchell returned after intermission to give a sparkling solo performance of "Big Yellow Taxi," which mourns the destruction of the environment with the lament, "You don't know what you got til it's gone."

At the end of the evening, Joni Mitchell was gone, but those who nearly filled The Auditorium knew very well what they had — too little of Miss Mitchell.

Tom Scott and the LA Express also preceded Miss Mitchell by themselves and amply demonstrated the best and worst aspects of thundering, highly amplified jazz and rock.