Niemeyer designed the Sambódromo in 1984 for one purpose: 70,000 spectators to see and hear Rio's samba schools march their 4,000-strong drum sections past at 130 BPM. The parade canyon is 700 metres long, 13 metres wide, raked seating on both sides, judges' stand in the middle. The bateria locks in around sector 9, lower-middle. The architectural achievement is acoustic. A samba school's percussion section, 400 surdo drummers walking past at 4 metres per second, would diffuse anywhere else. The Sambódromo channels it. The most music-specific venue in the Americas.
Sector 9 (lower middle, near judges' stand) is where the bateria locks in. Avoid the camarotes , they're hospitality, not music.
A venue engineered for one type of music. The most specifically architectural music venue in the Americas.
Rio Carnival main parade nights: Sunday and Monday of Carnival week (variable, late February or early March). Champions' Parade the following Saturday is the public version, half the price.
Carnival main parades on Carnival Sunday and Monday, 21:00 to 06:00. Champions Parade the following Saturday. Visit the empty Sambódromo year-round via the Sambadrome Museum (Wed-Sun 10:00-18:00).
Metro Praça Onze (Line 1), exit directly onto the parade route. From Copacabana, 30 minutes by metro. Sector 9 (lower middle, near judges' stand) is where the bateria locks in; book that sector if you can.