1. Samba schools throughout the year
Carnival isn’t the only time to experience the spectacle and beat of Rio’s samba schools. As soon as Carnival finishes many of these schools will start rehearsals for the following year.
These practice performances can be seen for cheap and will become more and more elaborate the closer it gets to Carnival, with full-dress rehearsals in the months just prior.
I’ve seen performances in October that were as professional as anything I’ve seen in the Sambadrome during Carnival. Details can be found at the Rio Carnival site.