DJ Fatboy Slim and U2 frontman Bono are taking part in Salvador's carnival, one of the world's biggest street parties.
Fatboy Slim will DJ on a giant float or "trio eletrico"
Between 1.5 and two million people are expected at the six-day event as bands move through the city on giant floats.
Bono - whose band U2 played Sao Paulo last weekend - performed a duet with Brazilian singer Ivete Sangalo on Thursday, newspaper O Globo reported.
Fatboy Slim, also known as Norman Cook, will help close the carnival on one of the floats, known as "trios eletricos".
These feature bands playing on top of trucks laden with speakers, following a 16-mile route through the Brazilian city.
Salvador's annual carnival has a lower international profile than the Rio de Janeiro carnival but is just as popular in Brazil.
U2 played in front of about 150,000 people in Sao Paulo
U2 played to about 150,000 fans in concerts on Monday and Tuesday.
Frontman Bono visited Brazilian president Luiz Inacio Lula da Silva and donated a guitar for auction to benefit his Zero Hunger anti-poverty programme.
Bono reportedly sang the U2 song Vertigo from a private box facing the carnival route on Thursday, while Sangalo and her band joined him from on top of a truck.