Common Definition

A cappella is a musical term of Italian origin that generally means "without accompaniment." The phrase a cappella is used to describe vocal music or singing without instrumental music to accompany the vocalists.

Literal Translation

According to Collegiate Christian A Cappella, the literal translation of a cappella from Italian to English is "in the style of the chapel," which doesn't necessarily mean the musical piece is sung without accompaniment.

Controversy

Because the literal translation from Italian to English is "in the style of the chapel," there is some debate about whether a cappella truly means without accompaniment. According to Collegiate Christian A Cappella, musical instruments can be used to strengthen vocal lines.

Spelling Inconsistencies

According to Singers.com, a capella is actually the Latin spelling. The commonly accepted spelling with two p's, a cappella, is the Italian spelling. Since other musical terms are Italian, such as accelerando or decrescendo, a cappella is the preferred spelling, although either is technically correct.

Modern Examples

Despite the spelling and definition debates, modern day a cappella includes doo-wop and barbershop quartets.

Source:

Collegiate Christian A Capella

Singers.com