Born in Buenos Aires, Trelles became first known in the 1970s thanks to his participation in the musical TV-show Siete y medio and later for winning the musical competition held in the TV-show Canciorena, which got him a contract with the record label RCA.

[1] During his career he recorded about two dozen albums and collaborated as a singer and a composer with important artists such as Sandro de América, Victor Heredia, Chico Novarro, Estela Raval, Rubén Juárez, Alberto Cortez, Raúl Lavié.

[1][2] His most important collaboration was with Astor Piazzolla, with whom he toured nationally and abroad as a member of his ensemble Octeto Electrónico, even performing at the Carnegie Hall.

[1][2] As a stage actor, Trelles got his first success starring in the 1979 musical Aggiungi un posto a tavola; he later played leading roles in numerous stage works, notably co-starring alongside Milva in a successful rendition of the Piazzolla-penned operetta María de Buenos Aires.

[1][2] In 2018 he released a collection of short stories, El Bar de Los Milagros.