Conductor John Nelson is noted as a specialist in choral-orchestral music, especially the works of Berlioz. He also built the Indianapolis Symphony Orchestra from a part-time group into a major American ensemble.

Nelson was born on December 6, 1941, in San José, Costa Rica. His parents were American missionaries, and he grew up amid religious choral music. Nelson attended Wheaton College, a Christian institution in Illinois, and went on to the Juilliard School in New York, where he studied conducting with Jean Paul Morel and won the school's Irving Berlin Award. After finishing his schooling, he worked as a freelance conductor in New York, leading some of the satirical P.D.Q. Bach performances created by composer-humorist Peter Schickele, conducting the Greenwich Philharmonia and New Jersey Pro Arte and serving on the Metropolitan Opera conducting staff. In 1972, he conducted Bizet's Carmen at the New York City Opera. A concert performance of Berlioz's Les Troyens, the first in New York, led to an engagement to conduct the work at the Metropolitan Opera in 1973 as a last-minute replacement for the ailing Rafael Kubelik. Nelson conducted Britten's Owen Wingrave at the Santa Fe Opera in the work's U.S. premiere.

In 1976, Nelson became the conductor of the Indianapolis Symphony. He programmed new music by Ellen Taaffe Zwilich and Charles Martin Loeffler, improved the group's sound, transformed it into a 52-week-a-year ensemble, restarted its recording career (he recorded Zwilich's Symphony No. 1 with the group in 1986), and moved it into the Circle Theater in downtown Indianapolis. Nelson began a stint as the music director of the Caramoor Festival in Katonah, New York, in 1983 and as the music director of the Opera Theatre of St. Louis in 1985. Suffering health problems, Nelson relinquished these positions in the late '80s and early '90s and returned to freelancing, largely in Europe. In addition to major American orchestras, he has conducted the Dresden Staatskapelle, the Oslo Philharmonic, and the Leipzig Gewandhaus Orchestra, among other major groups.

In 1998, he became the music director of the Ensemble Orchestral de Paris under a contract that called for 14 weeks of appearances a year. He led the group in a complete cycle of Beethoven symphonies released on the Ambroisie label in 2006. In 2008, he left the Ensemble Orchestral de Paris but has remained active as a guest conductor and recording artist; he also served as the artistic director of the choir Soli Deo Gloria. In 2019, he released a pair of acclaimed Berlioz recordings on the Erato label: the Requiem, Op. 5, with the London Philharmonic Orchestra and Choir and the opera La Damnation de Faust. He returned in 2022 on Erato with a recording of Berlioz's song cycle Les Nuits d'été, Op. 7, and the viola concerto Harold en Italie, Op. 16. By that time, his recording catalog comprised more than 30 items. ~ James Manheim, Rovi