Q. - Wasn't Joni Mitchell that talented young songwriter who wrote all those good songs (like "Both Sides Now") for Judy Collins?

A. - Uh huh, and now she is considered one of contemporary music's finest song stylists. The Canadian native is currently riding high on the charts with her latest LP, "The Hissing of Summer Lawns" (Elektra/Asylum label). Ms. Mitchell will perform Monday night with the L.A. Express at Memorial Coliseum.

It is the jazz-tinged backing of the Express that has made Ms. Mitchell's most recent recording efforts as musically memorable as her earlier lyric-dominated albums. It has been a big step from songs like "Chelsea Morning" to "Sitting in the Lounge of the Mayflower Hotel." [sic] That step was begun with the innovative "Blue" album in 1972 and was carried through in "Court and Spark," "Miles of Aisles" and "Summer Lawns."

It is ironic that the L.A. Express could become best-known as "Joni Mitchell's Band." Keyboard player Victor Feldman has performed with such notables as Cannonball Adderley and Benny Goodman. His sessions reputation has been enhanced through work with everyone from Barbra Streisand to Elvis Presley. Saxophonist David Luell, the group's most recent addition, has recorded with Cold Blood, the Pointer Sisters and Woody Herman. A sideman on the last two Joni Mitchell albums, guitarist Robben Ford has worked with the Charles Ford Blues Band and Jimmy Witherspoon.

Max Bennett, on bass, is an original Express member and his background includes recording with Peggy Lee, Frank Zappa and Barbra Streisand. Drummer John Guerin has performed on the last three Mitchell albums.

Joni Mitchell is no spotlight thief. Her band opens her concerts with a brief jazz set before joining The Star for a jazzy, fast-paced set. After the band retires to catch some wind, The Star performs a 40-minute solo set. The atmosphere is again enlivened with the return of the band for the duration.

Enraptured concert-goers in Austin, Tex., were recently treated to an unscheduled performer at the end of a Joni Mitchell concert. One Bobby Zimmerman was persuaded by Ms. Mitchell to do a couple songs, and, although he had trouble with his own lyrics on "Girl From the North Country" Bob Dylan created a near-riot just by his presence.

The Mitchell-Express tour covers 30 American dates before going to Hawaii, Australia, New Zealand, Japan, Scandinavia and Europe.