Carn was born Sarah Jean Perkins in Columbus, Georgia. She was encouraged by her parents to sing. At the age of four, she became a member of her church choir. She went on to learn to play the piano, the clarinet, and the bassoon, mastering all three. Carn attended Booker T. Washington High School in Atlanta, and learned to speak Russian fluently. She received a scholarship after graduating in 1965, to attend Morris Brown College where she performed every genre from musical theater to grand opera.
Carn planned on furthering her studies at Juilliard School of Music in New York City when she met and married jazz pianist Doug Carn (the couple later divorced) and became a featured vocalist in his jazz fusion band. The couple based themselves in Los Angeles, California, where Carn did three early albums with her husband, Infant Eyes, Spirit of the New Land, and Revelation on Black Jazz/Ovation.
In 1976, Carn was signed to Kenneth Gamble and Leon Huff's Philadelphia International Records; her debut album in 1977 Jean Carn (PIR 34394) was a classy affair that merged the best of '70s soul and jazz with solid songwriting and tight instrumental support (MFSB, Instant Funk). The debut single "Free Love" went to number 23 R&B. Several of the album's tracks received considerable radio airplay. In June 1978, her second album for the label, Happy to Be With You (PIR 34986), was released. It included the hit single "Don't Let It Go to Your Head".
Carn's third Philadelphia International album When I Find You Love (PIR JZ 36196) was more of a return conceptually (musically and sonically) to that of Jean Carn. Produced by Dexter Wansel, Gamble and Huff, and Jerry Butler, the album rates as one of Carn's best efforts. The smooth and halting "My Love Don't Come Easy" peaked at number 43 R&B in the summer of 1979. At this time Ms. Carn was switched from the Philadelphia International label to the subsidiary TSOP imprint for her final outing. Released in August 1981, Sweet and Wonderful a duet featuring Glenn Jones, containing a remake of the Spinners' "Love Don't Love Nobody," on which Carn sang all the backgrounds, which went to number 35 R&B.
With artistic and critical successes in tow, Carn moved to Motown Records in 1982, making her label debut with the album Trust Me. The single "If You Don't Know Me By Now," a cover of the Harold Melvin and the Blue Notes hit with backing vocals by The Temptations, went to number 49 R&B. A scheduled follow-up LP was canned and is reportedly in the vaults, following Ms. Carn's leaving the Motown roster. Her career continued and thanks to what she describes as her "devoted following", Carn continued to perform worldwide.
By 1986, Carn signed to Omni Records. Closer Than Close, produced by saxophonist Grover Washington Jr. was released in July of that year and the title track went to number one R&B. Her 1988 album You're a Part of Me included a hit cover of Aretha Franklin's "Ain't No Way," produced by Nick Martinelli. Carn later signed with Place One Entertainment, which reunited her with former Omni Records president Steve Bernstein, with her Love Lessons album.
In 2002, Carn toured the United Kingdom accompanied by her musical director, Nathan Heathman, with appearances at the London Jazz Cafe in March of that year. Numerous visits to Europe followed. 2003 saw the release of Collaborations, an album for the Expansion Records label. In 2008, she was among the Philly artists featured in the two-part PBS television special "Love Train, The Sound of Philadelphia" which celebrated the musical legacy of Kenny Gamble & Leon Huff and Philadelphia International Records.