Gabriel Espinosa was born in Mérida, the capital of the Mexican state of Yucatán, in 1952, into a family where his mother encouraged him onto the guitar at six. By fourteen he had switched to electric bass and was working professionally with his brothers Victor and Patricio in the family group Los Deltons, whose first recording was Eric Germon's "Eres Joven," the winning song at Mérida's Dosis festival in 1971. The other formative sound arrived through the port city's touring circuit. Brazilian bands passing through Mérida on their way north brought bossa nova with them in the early 1960s, and he has dated his attachment to the music precisely: "I remember being 14 years old, listening to those great Brazilian players who would come through Merida on their tours." Boleros, the Beatles and Antonio Carlos Jobim all reached him in the same few years, and the combination has run through everything he has written since.

He came to the United States in 1976 on a music scholarship to Central College in the small Dutch-founded town of Pella, Iowa, and took a BA in music there. Berklee College of Music followed, and he graduated magna cum laude in 1983 with a degree in arranging. In his final Berklee year he co-founded the band Ashanti with the Swiss alto saxophonist George Robert, a classmate; they worked around Boston for a year before Espinosa relocated the group to Cancún, where it held down steady work from 1984 to 1991. He entered the jazz studies program at the University of North Texas in 1992, took a master's degree in 1995, and sang in the UNT Jazz Singers under Paris Rutherford, whose reading of Clifford Brown's "Daahoud" from the group's 1995 album Geraldine was picked for the school's fiftieth-anniversary box set; the vocal soloist on it is Alison Wedding, who would sing on his own records fifteen years later. During the same period he produced records for Mexican artists, working for six months alongside the Yucatecan songwriter Armando Manzanero as co-producer on a pair of Manzanero's own projects.

In 1996 he returned to Central College as Director of Jazz Studies. He ran the jazz band, taught applied lessons, and founded the Vocal Combos program, later renamed ALMA, which pairs a singer with a small band and pushes students to write their own material. From 2004 he also directed the Latin American Ensemble at Grinnell College, and he held both appointments for the better part of two decades. Iowa also gave Ashanti a second life. Espinosa rebuilt the band in Pella out of local rhythm-and-blues and jazz players and recorded three albums with it for Edgewater Group: En Fuego (2001), Sin Fronteras (2003) and Dyos Bo'otik (2004), the last titled with the Mayan phrase for "thank you." The band toured the Midwest and Mexico with guests including Alex Acuña, Anat Cohen, Gil Goldstein and Dave Samuels. In January 2008, marking forty years in music, he brought a version of the group billed as Ashanti Mundo to the Teatro José Peón Contreras in his native Mérida, with George Robert on saxophone, Edsel Gomez on piano, Claudio Roditi on trumpet and Tim Crumley on drums.

His first album under his own name was cut in Brooklyn in November 2008 and released as From Yucatán to Rio (ZOHO ZM 200907) on July 14, 2009. It set the pattern for everything after it: an international cast assembled around his own writing, with Roditi and George Robert on the front line, Helio Alves on piano, Romero Lubambo on guitar, Antonio Sánchez and Adriano Santos splitting the drum chair, Anat Cohen guesting on clarinet, Alison Wedding singing, and Darmon Meader and Kim Nazarian of the New York Voices on the opening "Agua de Beber." He was explicit about what the record was not. "I see myself more like a composer and an arranger than a soloist," he told the label, laughing off the idea of a bass-hero project.

The partnership that made his name outside the Midwest began at Central College, where the German-born harmonica player Hendrik Meurkens came to perform in 2011. The two found a shared taste for songs with strong melodies, agreed to split the writing evenly, and recorded Celebrando in Brooklyn from May 24 to 27, 2011. Released on April 10, 2012 as ZOHO Music's hundredth CD, it carries Anat Cohen on clarinet for three pieces and tenor saxophone for a fourth, Antonio Sanchez sharing the drums with Mauricio Zottarelli, and Jim Seeley on trumpet and flugelhorn. The album spent twenty-six weeks on the JazzWeek chart and finished at number twenty-five on that publication's list of the year's records, and the group played it at Dizzy's Club Coca-Cola at Lincoln Center on July 15, 2013. A second Meurkens collaboration, Samba Little Samba, was recorded on December 10 and 11, 2013 and released on November 11, 2014, with Cohen again on clarinet and tenor, Tierney Sutton joining Espinosa to sing his arrangement of "Bésame Mucho," and Adriano Santos alternating with Sánchez at the kit. That same October the Greater Des Moines Community Jazz Center selected Espinosa unanimously for the Iowa Jazz Hall of Fame, and he was inducted at Altoona on October 19, 2014, citing his students as the reason for the award.

Four more albums followed on ZOHO. Songs of Bacharach and Manzanero (October 7, 2016), recorded across December 2015, January and March 2016, sets five Burt Bacharach songs sung by Tierney Sutton against five Manzanero boleros sung in Spanish by Espinosa, with Meurkens on harmonica for four tracks. Nostalgias De Mi Vida (October 5, 2018), taped in Brooklyn that March, is the most autobiographical of them, built around Kim Nazarian's voice, Joel Frahm's tenor and Christian Jacob's string arrangements, and it circles back to "Eres Joven," the first song he ever recorded with Los Deltons. Bossas & Boleros (June 23, 2023), cut in Brooklyn and in Cedar Falls, Iowa in September and December 2022, brought in Fred Hersch for two voice-and-piano boleros, the New York Voices for a vocal-quartet arrangement of "Sing," and Cohen on clarinet for the Yucatecan jarana "Mi Jarana." The Brazilian Project (Origin Records 82952), released on May 22, 2026, is the furthest he has taken the composer-first idea: assembled between 2022 and 2025, arranged by the trombonist Rafael Rocha and the flugelhornist Bruno Santos, recorded in Rio de Janeiro by a Brazilian nonet with strings added in Tallinn, and played entirely without him. He is now emeritus professor of music at Central College.

Espinosa is a bandleader whose instrument is really the arrangement. He plays electric and acoustic bass with a supporting player's economy, frequently hands the bass chair on his own records to Gustavo Amarante or Joe Martin, and on The Brazilian Project stepped off the bandstand entirely, which is an unusual thing for a bassist to do to his own music. What he keeps is the writing. His originals sit on the seam between the Yucatecan repertoire he grew up with, the Brazilian forms he adopted at fourteen, and jazz harmony, and the most distinctive of them are the jarana pieces, the 6/8 dance meter of Yucatán, which he has used to open a door onto material that has almost no other presence in jazz. "Encuentro Maya," "Maya Roots" and "Mi Jarana" all work that vein, and Hendrik Meurkens has said the Mayan atmosphere in Espinosa's songs was something he had not heard in jazz before. The other constant is the voice used as an instrument: Alison Wedding singing melodies wordlessly in the horn line on Celebrando, three-part vocal harmony carrying the theme where a horn section would, and the vocal-jazz craft he learned in the UNT Jazz Singers and teaches at Central. He sings the boleros himself in Spanish without any pretence about it. "I'm not trying to show that I have this tremendous voice," he has said. "It's about telling the story." He calls himself a hybrid composer rather than a purist of any one tradition, and reviewers have generally taken him at his word: Dan Bilawsky, writing in All About Jazz, credited him with delivering the Bacharach and Manzanero songbooks as he heard them without twisting either for the sake of a modern slant, and Bill Milkowski wrote that the auspicious ZOHO debut was bound to take him a giant leap forward in his career.