Founder (in 1963) and leader of the memorable samba-jazz group Copa 5, (Manuel Gusmão, bass; Luís Carlos Vinhas, piano; Dom Um Romão, drums; and Pedro Paulo, bass), J. T. Meirelles recorded with the group in 1964 the landmark LP O Som, signing the arrangements for the tracks "Quintessência," "Solitude," "Blue Bottle's," "Nordeste," "Comtemplação," and "Tânia," all written by himself. The next album, O Novo Som, brought a new formation with Eumir Deodato (piano), Edson Machado (drums), Roberto Menescal (guitar), Waltel Branco (electric guitar) and Manoel Gusmão (bass), with the originals "O Novo Som," "Solo," and "Serelepe." Meirelles worked throughout his career with instrumental groups like Azymuth, Hermeto Pascoal's, Helvius Vilela's, Antônio Adolfo's and João Donato's, having also backed vocalists/instrumentalists Jorge Ben, Agostinho dos Santos, Silvinha Telles, Edu Lobo, and Rosinha de Valença, among others. Out of the spotlight in the '80s and '90s, he was rediscovered by journalist José Domingos Raffaelli in 2000, who invited him for the jazz sessions held at the bar of the Hotel Novo Mundo (Rio de Janeiro), which brought him to the instrumental music forefront again. In 2001 the LP O Som was reissued in CD by Dubas Música and O Novo Som was re-masterized.
Having started in music at eight, J. T. Meirelles studied composition and arranging at Berklee School of Music (Boston, MA). His professional debut was at 17 as João Donato's saxophonist. Next he moved to São Paulo, where he worked with Luís Loy. Returning to Rio in 1963 Meirelles formed the Copa 5, which debuted at the Bottle's Bar, at the Beco das Garrafas (Rio). In that same year he wrote the arrangement for the original recording of "Mas Que Nada," Jorge Ben Jor's first hit. From 1964 to 1975 he worked as an instrumentalist, conductor, arranger, and producer at Odeon. In 1965 and 1967 he wrote several arrangements for different editions of the historic Festival Internacional da Canção (International Song Festival, TV Globo), having performed in 1966 in the Berlin Jazz Festival (Germany), with Edu Lobo, Rosinha de Valença, Dom Salvador, and Sérgio Barroso. In 1967 he participated in the inauguration of the Canecão room (Rio), working there during the entire year. From 1969 to 1971 Meirelles was EMI-Odeon's (São Paulo) A&R, where he performed regularly with the Luís Loy Quinteto. Back to Rio in 1971 he resumed his work at EMI-Odeon until 1975. Moving then to Mexico, he was hired by the Gimmicks of Sweden, with which he moved to Europe, where he lived for several years (France, Sweden, and Monte Carlo), working with several orchestras (like Aimée Barelli's).