Coro vs. coral
While both coro and coral relate to groups of singers, their usage depends heavily on the region. Coro is the universal term used in both Portugal and Brazil, whereas coral is used as a noun for a singing group primarily in Brazil.
Coro
B1This is the standard term for a choir or chorus in classic Portuguese and is the preferred word in Portugal for any singing group. In Brazil, coro is also used, often interchangeably with coral, but it is specifically preferred when referring to opera, theater, professional backing vocals, or the act of people singing in unison.
O coro da catedral de Lisboa é muito antigo.
(The Lisbon cathedral choir is very old.)
Eles cantaram o parabéns em coro.
(They sang happy birthday in unison.)
O compositor escreveu uma peça para coro e orquestra.
(The composer wrote a piece for choir and orchestra.)
Ela faz parte do coro da ópera municipal.
(She is part of the municipal opera chorus.)
Não gosto do coro desta música pop.
(I do not like the backing vocals of this pop song.)
Coral
B2In Brazil, this word is commonly used as a noun to refer to a specific organized singing group, such as a school, church, or community choir. However, in Portugal, coral is almost exclusively an adjective (meaning choral or related to a choir) or refers to the marine animal; it is rarely used as a noun for the group itself in European Portuguese.
O coral da escola vai se apresentar no Natal.
(The school choir will perform at Christmas.)
Minha mãe entrou para um coral comunitário.
(My mother joined a community choir.)
Nós assistimos a um espetáculo de música coral.
(We watched a choral music show.)
O coral da universidade busca novos tenores.
(The university choir is looking for new tenors.)
Este arranjo coral é muito difícil de cantar.
(This choral arrangement is very difficult to sing.)
Summary
Use coro as the safe, universal option for choir in all Portuguese-speaking countries. In Brazil, feel free to use coral when referring to specific groups like church or school choirs. In Portugal, avoid using coral as a noun for the group; strictly use coro instead.