A________is a mechanical or electronic device used to keep a steady tempo.

A. Metronome
B. Cresendo
C. Ritardano
D. Bar line

Its A. Metronome

thank u !

The correct answer is A. Metronome.

To arrive at the answer, you can use your general knowledge or conduct a quick Google search. Alternatively, you can break down the question and analyze the answer choices.

First, let's understand what is being asked. The question mentions a device used to keep a steady tempo. Tempo refers to the speed at which a piece of music is played.

Now let's examine the answer choices:

A. Metronome: This is a device, both mechanical and electronic, which helps musicians maintain a steady tempo by producing an audible click or beep at a specified beats-per-minute (BPM). This fits the description in the question and is therefore a possible answer.

B. Cresendo: Crescendo refers to a gradual increase in volume or intensity in music, not a device used to keep tempo. This choice does not fit the description and can be eliminated.

C. Ritardando: Ritardando is a musical term indicating a gradual decrease in tempo. It does not refer to a device but rather describes a change in tempo during a performance. This choice does not fit the description and can be eliminated.

D. Bar line: A bar line is a vertical line used in musical notation to divide music into measures. It is not a device used to keep tempo. This choice does not fit the description and can be eliminated.

By analyzing the answer choices and their definitions, we can determine that A. Metronome is the correct answer.