Bio from Howard's site:
One of the top tuba soloists since the early '60s, Howard Johnson is a very versatile player who not only plays tuba and baritone but other reeds and trumpet. He moved to New York in 1963, where he worked with Charles Mingus (1964-1966), Hank Crawford, and Archie Shepp. In 1966, he started a 20-year off-and-on association with Gil Evans. Johnson's four-tuba group Substructure performed with Taj Mahal, and, in the late '70s, he formed a different tuba band called Gravity that, in 1996, finally had the opportunity to record (plus play at the Monterey Jazz Festival). Howard Johnson has recorded with Crawford (1983-1984), Jack DeJohnette's Special Edition, Jimmy Heath, Bob Moses, George Gruntz's Concert Jazz Band, and frequently with Evans' orchestra, among others.