Isaac Oviedo was born on July 6, 1902, in the village of Sabanilla del Encomendador (now known as Juan Gualberto Gómez) in the municipality of Unión de Reyes, Matanzas, Cuba. His family was poor and his mother worked as a sugarcane cutter. From an early age he taught himself to play the guitar. At age 11 he learned to play the tres from a musician from Santiago de Cuba who had relocated to Matanzas after the War of Independence. By his late teens he was playing in Pepito López's orchestra, and also formed his own band, Los Unionenses. He played at the Sauto Theater, and in 1922 founded the Sexteto Matancero alongside guitarist Julio Govín. He then took his group to Havana in 1926, as many other rural artists were doing at the time. Between 1926 and 1928 he played at various bars and cabarets in Marianao, the most touristic seaside neighbourhood of Havana. In this period Graciano Gómez joined the band on guitar and Barbarito Díez became the lead singer. With them, the Sexteto Matancero held its first recording sessions on February 7, 1928, for Victor. They recorded "Engancha carretero", Oviedo's most successful and critically acclaimed song, noted for its creole character.