In referring to singing unaccompanied by instruments, the traditional spelling is the Italian one, a cappella: two words, two Ps, two Ls. The one-word spelling “acapella” is widely used by Americans, including by some performing groups, but this is generally regarded by music experts as an error. ...

Is a cappella a noun or adjective?

a cappella • \ah-kuh-PEL-uh\ • adverb or adjective. : without instrumental accompaniment.

What is the proper spelling of a cappella?

A cappella (/ˌɑː kəˈpɛlə/, also UK: /ˌæ -/, Italian: [a kkapˈpɛlla]; Italian for 'in the style of the chapel') music is a performance by a singer or a singing group without instrumental accompaniment, or a piece intended to be performed in this way.