I believe you're referring to "a capella" which means without accompaniment.
I will sing this song a cappella.
A cappella became prominent in the Renaissance era.
Cappella Sansevero was created in 1590.
Cappella Istropolitana was created in 1983.
Cappella Paolina was created in 1540.
The population of Cappella Maggiore is 4,576.
PandemoniUM - A cappella - was created in 1993.
Cappella Coloniensis was created in 1954.
A Cappella Live was created in 1993.
The population of Olmi-Cappella is 188.
Frankly a Cappella was created in 2000.
Best A Cappella was created on 2002-09-25.