In music terminology, the Italian phrase “a cappella” refers to which type of performance style?

Introduction / Context:
The term a cappella is often seen in descriptions of choirs, vocal groups, and arrangements of popular songs. It is an Italian musical expression that has a specific meaning in performance practice. This question checks whether you understand what kind of musical performance is indicated when something is described as a cappella.

Given Data / Assumptions:
- The term is used in musical contexts, not in literature or visual arts.
- It is associated with singing and vocal music.
- The options include various art forms and contexts, but only one matches standard music terminology.

Concept / Approach:
A cappella literally means in the manner of the chapel in Italian. Historically, it referred to choral music that was performed in chapels without instrumental accompaniment, relying solely on voices. In modern usage, a cappella means any vocal performance or arrangement sung without instruments, whether in classical choral music, barbershop quartets, or contemporary vocal groups. Instruments may sometimes be mimicked by voices, but no real instruments are played.

Step-by-Step Solution:
Step 1: Recognize that a cappella is a musical term and not used primarily in literature or visual arts. Step 2: Recall the historical association of a cappella with church choirs singing without instrumental backing. Step 3: Understand that in contemporary music, a cappella arrangements feature only voices, with no piano, guitar, or other instruments. Step 4: Compare options and identify which one explicitly refers to vocal music without instruments. Step 5: Select vocal music performed without instrumental accompaniment as the correct description.

Verification / Alternative check:
Music dictionaries define a cappella as choral or vocal music without instrumental accompaniment. Concert programs and album descriptions use the term this way for both classical works and modern pop arrangements. This consistent usage in musical contexts confirms that a cappella refers to purely vocal performance.

Why Other Options Are Wrong:
Option A: Literature is a separate art form; while poems may be set to music, the term a cappella does not refer to poetry readings alone.
Option C: Visual arts such as painting and sculpture are not described as a cappella; the term is specific to musical performance.
Option D: War songs and military music may be sung with or without instruments, but a cappella does not mean war related music; it simply describes the absence of instruments.

Common Pitfalls:
Some learners mistakenly think that a cappella means choir music only, but it can also apply to solo or small group singing as long as no instruments are used. Another pitfall is confusing a cappella with acoustic performance; acoustic refers to instruments played without electronic amplification, while a cappella refers to voices without instruments at all.

Final Answer:
The correct answer is vocal music performed without instrumental accompaniment because a cappella describes singing that relies solely on voices and does not use instruments.