Rocanroles Sin Destino is Callejeros telling you why they picked a life on the road with a rock band, and why they would pick it again.
The song opens with doubt. The singer spends his days "relojeando al cielo desde el suelo" (eyeing the sky from the ground), not sure if "este tren solo de ida" (this one-way train) will ever give him a place. Relojear is Rioplatense slang for sneaking a look at something, so picture someone glancing up at a goal he cannot reach yet.
Then the music wins the argument. "Cuando se quiebran todos los sentidos con una canción" (when every sense breaks with a song), that noise works "como abogado" (like a lawyer) and sets his reason free. The goal is to be "la revancha de todos aquellos" (the payback for all those) who fought and "no pudieron reír sin llorar" (could not laugh without crying).
The second verse is angry, and it is the best part. The industry only calls "si pagas bien o si le tiras la alfombra" (if you pay well or roll out the carpet for them), and "tantos mediocres sin clase" (so many classless mediocrities) build a ranking of the chosen ones. His answer: what counts is "lo que se siente en la calle" (what you feel in the street), with the people. By the last chorus, una canción has turned into un rocanrol, which is just how Spanish speakers spell rock and roll.