Tessa Souter was born in London on April 3, 1956, to a Trinidadian father and an English mother, and by her own account has been singing since she was three, encouraged by a mother who was herself a fine singer and worked as an artist's model. She took piano lessons from eight to twelve, then taught herself guitar by ear so she could accompany her own voice. The household was unsettled in every sense: she went to sixteen schools, and at twelve she was told that the man who had raised her was not her biological father, who she was then told had been a Spanish flamenco dancer killed in a plane crash. At sixteen she left home, married, had a child, and was a single parent at eighteen. She went back and sat her O and A levels afterwards, and took a degree in English Literature at Queen Mary College, London University.

What followed was not a music career but twenty years of print journalism. She started in editing jobs, first at an engineering company and then at Parents magazine, before going freelance and writing for Elle, Elle Decoration, Cosmopolitan, Vogue and House Beautiful, and for the Times, the Guardian, the Independent, the Daily Telegraph, the Sydney Morning Herald and the South China Morning Post. She moved to the United States in 1992 and settled in San Francisco, where she was one of the founding members of the writers' collective The Writers Grotto alongside Po Bronson, Ethan Canin, Ethan Watters, Josh Kornbluth and David Munro. The second revelation about her parentage came at twenty-eight: her biological father was not Spanish but Black, and he was alive. She found him, met him, and came away with photographs, which is where the album she made three decades later begins.

Music restarted at San Francisco open mics, which she went to for fun rather than as a plan. She moved to New York in 1997 and kept sitting in around the clubs until enough musicians told her to take it seriously. A scholarship took her briefly to the Manhattan School of Music, where she met Mark Murphy, who offered her four years of study with him in exchange for running his workshops and private classes. She names Sheila Jordan as her other significant mentor. Her first professional booking was at New York's Caffe San Marco in February 1999, five years before there was a record to sell.

Listen Love arrived in 2004 on Nara Music, self-produced, cut at Tedesco Studios with Freddie Bryant on guitar, Mark Berman on piano, Essiet Essiet on bass and Wilson "Chembo" Corniel on percussion, and Miles Okazaki added on guitar for the closing "The Creator Has a Master Plan." It set the pattern for everything since: material other singers leave alone, opened up from the outside. Jimmy Rowles's "The Peacocks" and Mal Waldron's "Left Alone" sat next to Sting's "Fragile." The Japanese label Venus Records then invited her to record, and Nights of Key Largo (2008) put her in front of an all-star band, Kenny Werner on piano, Jay Leonhart on bass, Romero Lubambo on guitar, Joel Frahm on saxophones and Billy Drummond on drums, produced by Tetsuo Hara and Todd Barkan. Obsession (Motema, 2009) was the rock record, in a fashion: "Eleanor Rigby," Cream's "White Room" and Nick Drake's "River Man" rebuilt with accordion and violin over a guitar trio.

Beyond the Blue, cut at Avatar Studios in New York on March 27 and 28, 2011, is the record that made her name outside the clubs. She wrote her own lyrics to themes by Beethoven, Chopin, Ravel, Borodin, Faure, Schubert, Brahms, Debussy, Albinoni and Rodrigo, and sang them with Steve Kuhn on piano, Joe Locke on vibraphone, David Finck on bass, Gary Versace on accordion, Joel Frahm on saxophone and Drummond on drums. Venus issued it in Japan in July 2011; Motema licensed it and released it internationally in May 2012; and when it reached Britain in 2013 the Sunday Times magazine named it one of its Top Ten Jazz Records of the Year, on a list with Ahmad Jamal, Gregory Porter and Stacey Kent. In 2015 she became one of four musicians, out of roughly four thousand who played the Rochester International Jazz Festival that year, chosen by WXXI to be taped for a one-hour public television special; her set was recorded on June 21, 2015 and broadcast nationally on PBS stations. She has played Rochester seven times.

Picture in Black and White, released October 5, 2018 on her own Noa Records imprint and recorded at Systems Two in Brooklyn, is the album about her father. A DNA test had turned up seven African countries in her ancestry along with Carib, Scandinavian, Irish, English and Scottish lines, and the programme follows that map: Ayub Ogada and Mbarak Achieng's Luo song "Kothbiro," McCoy Tyner's "Contemplation" with a Vicki Burns lyric, Terry Callier's "Dancing Girl" run into U2's "Where the Streets Have No Name," Jon Lucien's "Child of Love," the English ballad "Reynardine," Ornette Coleman's "Lonely Woman," Milton Nascimento's "Nothing Will Be As It Was," and three Souter originals including the title song, a bass-and-guitar duet about a father she knew mostly as an old photograph. Her band was Adam Platt (piano), Yotam Silberstein (guitar and oud), Dana Leong (cello), Yasushi Nakamura (bass), Drummond (drums and cymbals) and Keita Ogawa (percussion). It became the second of her albums named a Sunday Times Top Ten Jazz Record of the Year, and was voted the year's best vocal jazz record by Ken Dryden in the New York City Jazz Record, by W. Royal Stokes, and by Jay Hunter at WVCR. Its fifth track carries the credit she is proudest of: Wayne Shorter granted her shared writing on "Ana Maria" for the lyric she wrote to it, and in 2024 Kurt Elling asked her permission to extend that lyric and recorded the result on Wildflowers Vol. 1.

Seven years later came Shadows and Silence: The Erik Satie Project (Noanara, June 27, 2025), her lyrics to the Gymnopedies and Gnossiennes set to jazz arrangements by pianist Luis Perdomo, with Nakamura, Drummond, saxophonist Steve Wilson and trumpeter Nadje Noordhuis. Two of its non-Satie pieces are borrowed lyrics rather than her own: Cassandra Wilson's words to Shorter's "E.S.P." and a reading of Ron Carter's "Mood." The album was made across four years of deaths, her "chosen uncle," her mother, the saxophonist Sheila Cooper, the singer Mansur Scott, and one wedding: she and Drummond married after fourteen years together. Germany's Audio Stereoplay named it the best vocal jazz album of 2025. Souter also published a book, Anything I Can Do You Can Do Better: How to Unlock Your Creative Dreams and Change Your Life (Vermillion/Penguin, 2006), and still teaches.

Souter sings low, with the sonority and breath control of a classical contralto and almost no ornament, and her whole method is repertoire: she goes looking for songs that jazz singers have not already worn smooth, then rewrites them from the inside. That has meant classical themes with her own lyrics on Beyond the Blue, Cream and Nick Drake on Obsession, Luo and Celtic folk song on Picture in Black and White, and Satie in 2025. Mark Murphy taught her for four years and Sheila Jordan calls her "a natural born singer," and both lineages show, Murphy in her willingness to treat a song as a narrative rather than a vehicle, Jordan in the exposure she tolerates: two of her records lean on duets with a single instrument. DownBeat gave her four stars and reached for "butterscotch timbres"; the Sunday Times wrote that she "raises songs to the level of poetry"; All About Jazz put her phrasing beside Billie Holiday's for poise and economy. The lyric writing is now the part of the work other musicians come to her for. Wayne Shorter gave her a shared writing credit on "Ana Maria," Kurt Elling recorded that lyric with additions of his own, and Vicki Burns, who wrote words for two of Souter's tracks, went on to record a Souter song of her own.