Maynard Solomon founded Vanguard Records together with his brother Seymour Solomon in 1950. The label was one of the prime movers in the folk and blues boom for the next fifteen years. As well as producing many albums, he was a prolific writer of liner notes.

Vanguard's first signing was The Weavers. They generated the first major commercial success for the label with The Weavers' 1955 concert at Carnegie Hall. Solomon also acquired the rights to record and release material from the Newport Folk Festival, which meant he could issue recordings by artists who were not actually signed with Vanguard. For this period Elektra was the main competitor for folk artists. Their singers Phil Ochs and Judy Collins were recorded at Newport, as was Bob Dylan from the Columbia label.

Solomon insisted on a clean appearance on stage, and clear diction, a view that reflected a large segment of public opinion at the time. More bravely, Solomon's label signed Paul Robeson at the height of the McCarthy era.

In 1960 he signed Joan Baez. In 1962 the label recorded Odetta at the Town Hall, New York, one of her best albums. The Rooftop Singers recorded "Walk Right In" in 1963, a hit on both sides of the Atlantic. Solomon produced it as well as other songs by the band. Unfortunately their next single "Tom Cat" was banned for being slightly suggestive, though it is tame by modern standards. It was probably the influence of Solomon that induced Joan Baez to record "Bachianas Brasileiras No. 5" by Villa-Lobos.

Solomon's belief in Marxism was a driving force in these early years, but it wasn't until 1973 that his writings explicitly reflected this. His 1973 book Marxism and Art is one of the books on Marxism from this period that has been continuously in print.

In the late 60's Vanguard had some success with rock artists, most notably "Country Joe and the Fish" (today usually called Country Joe McDonald). There were also some recordings of jazz, blues and disco that have not stood the test of time. One of the most surprising signings that he made in 1969 was Michael Szajkowski, an electronic composer. The material was borrowed from Handel, but the sound, on a synthesiser, was far from classical. His brother Seymour, however, had previously signed humorous electronic music artists Jean-Jacques Perrey and Gershon Kingsley in 1965. The team's work, proved to stand the test of time, and their Vanguard music is still used on commercials, on children's television, among a couple of examples. He continued to work with folk artists up to the 1980s but then moved towards classical music.

Solomon later embarked on a second career as a musicologist, notably as author of composer biographies, and his work (particularly his studies of Mozart and Beethoven) has met with some critical acclaim.

Characteristic of Solomon's approach is a careful sifting of the scholarly evidence, often with the goal of supporting new hypotheses about the events or motivations of the great composers and the people they knew (for instances cited in this encyclopedia, see Maria Anna Mozart, Mozart's Berlin journey, Mozart's name, and Antonie Brentano). A great deal of effort seems to reside in the attempts to compare and contrast certain ideas that need to be analyzed. Solomon is also careful to avoid uncritical repetition of old formulae in composer biographies; for example, like other recent biographers, he suggests that the final year 1791 of Mozart's life was one of personal revival, cut off by illness, rather than the steady slide into the grave that characterizes the traditional account. Most boldly, Solomon has not hesitated to offer specific psychological analyses and diagnoses of his subjects. He has, however, been criticized for anachronistic assumptions and a lack of understanding of eighteenth- and nineteenth-century German.

Solomon became, in 1997, a member of the International Musicology Society, and addressed its congress in London. He is the author most recently of Mozart: A Life, a finalist for the Pulitzer Prize in Biography, which won the Deems Taylor Award, as did his biography of Beethoven, and his study of Charles Ives. His Beethoven Essays won the Otto Kinkeldey Award for the most distinguished book on music published in 1988.

An associate editor of American Imago, and co-founder of the Bach Guild, he has also published articles in applied psychoanalysis and has edited several books on aesthetics. His current projects include a life of Schubert and a book tentatively titled Beethoven: Beyond Classicism. He has held visiting professorships at Yale, Harvard, and Columbia, and is currently on the graduate faculty of the Juilliard School.