Joni Mitchell and Donald Fagen were just two of the countless kids who grew up in small towns in the '50s and who heard jazz as a secret language that would give them access to high style and subtle sophistication. Like the bravest of their generation, Mitchell and Fagen made that intimidating cross-cultural journey and learned the language. They were right: Jazz did give a special eloquence to their small-town dreams, and never more so than on their newest albums. These records are not jazz albums but pop autobiographies in a jazz dialect that should ring true to anyone who has made a similar journey from the provinces to coolsville.

Joni Mitchell's "Wild Things Run Fast" (Geffen GHS 2019) is her first studio album since "Mingus," her 1979 collaboration with the late jazz composer. Donald Fagen's "The Nightfly" (Warner Bros. 23696-1) is his first solo album after 10 years as co-leader of the premiere jazz-rock group, Steely Dan. Both albums feature guitarist Larry Carlton, members of Toto and top notch jazz saxophonists--Wayne Shorter on Mitchell's and Michael Brecker on Fagen's. Each album includes a rhythm & blues chestnut by Jerry Leiber & Mike Stoller: Mitchell remakes Elvis Presley's 1959 "Baby, I Don't Care"; Fagen remakes the Drifters' 1956 "Ruby Baby." In each case the childhood rock 'n' roll favorite has been given a jazz arrangement to show how far the singer has traveled but also to prove that it's all one road.

Each album begins with a wistful, ironic look back at adolescence. Mitchell's "Chinese Cafe" describes a reunion with an old girlfriend from the days when they played the Righteous Brothers' "Unchained Melody" on the juke box at the Chinese Cafe in Fort McLeod's, Alberta. The memories give way to the lament, "nothing lasts for long," but Mitchell slips in snatches of "Unchained Melody," and its undying adolescent idealism strains against her middle-aged fatalism. Mitchell uses jazz phrasing and jazz arrangements to slowly alter the connotations of both the lament and the interpolated song.

Fagen's album begins with his new hit single, "I.G.Y. (What a Beautiful World)." The International Geophysical Year was 1957-58 when Fagen turned 10 and when he and many Americans were naive enough to believe that technology was about to usher in a utopian age. Fagen doesn't have to mention how that optimism was shattered to produce his irony; all he has to do is place the ebullient optimism historically and then deliver it with his familiar wry voice. He has fashioned a rich pop tune and bouncy beat, but an all-star horn section fills out the harmonies with unmistakable sadness.

On her 1975-79 albums, Mitchell used her growing infatuation with jazz to free her from the metrical and melodic demands of pop. Unfortunately, she often lost the focus and momentum of her songs in the process. On "Wild Things Run Fast," she returns to short, even lines and recurring, memorable melodies. Far from weakening the jazz elements in her music, this shift gives them more substance to color and elaborate. "Moon at the Window," for example, is a solidly written folk song about romantic desertion, but it's given unusual depth as Larry Klein's bell-toned bass notes resonate with ache and as Wayne Shorter's high, lonely soprano sax duets with Mitchell's high, lonely soprano voice.

Most of the songs describe the slippery, transient nature of modern romance; the slippery, ever-shifting jazz arrangements underscore the lyrics. Yet the album ends with a glowing affirmation of "Love." Adapting lyrics from St. Paul's famous epistle to the Corinthians, Mitchell's intuitive phrasing makes the biblical verses breathe like a jazz song as Shorter's soprano sax calls out the sensual side of love.

Fagen's liner notes describe the songs on "The Nightfly" as "certain fantasies that might have been entertained by a young man growing up in the remote suburbs of a northeastern city during the late '50s and '60s, i.e., one of my general height, weight and build." Fagen proves very good at capturing that time in life and that time in history.

"New Frontier" manages to combine fall-out shelters, Tuesday Weld, Dave Brubeck and the title phrase, all in a desperate effort to seduce a teen-age girlfriend. In the same vein is "Maxine," a girlfriend the singer woos in a suburban shopping mall with visions of Mexico City and Manhattan. Such visions are supplied by "The Nightfly," the graveyard shift jazz disc jockey who teaches the teen-age singer through a bedroom transistor radio. Throughout all these songs runs a naive suburban optimism that is impatient with its own limitations. Only one song, "The Goodbye Look," suggests the souring of the American Camelot with its hints of Cuban revolutionaries who don't play by the rules.

The last Steely Dan album, the 1980 "Gaucho," seemed too clever for its own good. The ornamental arrangements and elliptical lyrics by Fagen and partner Walter Becker completely obscured the emotional point of the songs. On his solo album, Fagen has given the lyrics more specific situations and has sharpened his melodies into hooks, especially on "Maxine" and "The Goodbye Look." Steely Dan producer Gary Katz has stripped back the production to let the songs stand on their own more. Just the same, "The Nightfly" sounds so much like vintage Steely Dan that one has to wonder just what the absent Walter Becker contributed to the old records.