Muzica a încetat.

Muzică means music in the general sense.

Muzica means the music. Romanian usually puts the definite article at the end of the noun instead of using a separate word like English the.

So:

• muzică = music
• muzica = the music

With many feminine nouns ending in -ă, the definite form changes that ending to -a:

• casă → casa = the house
• muzică → muzica = the music

So in this sentence, muzica is specifically the music.

Here, a is an auxiliary verb used to form the compound past in Romanian, called perfectul compus.

So:

• a încetat = has ceased / stopped

This a is the 3rd person singular form of the auxiliary used in this tense.

A very useful pattern is:

• am = I have
• ai = you have
• a = he/she/it has
• am = we have
• ați = you all have
• au = they have

Because muzica is singular, Romanian uses a.

A încetat is in the perfectul compus, the most common past tense in everyday Romanian.

Depending on context, it can often be translated as:

• The music stopped.
• The music has stopped.
• The music ceased.
• The music has ceased.

In many situations, English chooses between simple past and present perfect, but Romanian very often uses this same tense for both.

No. They look similar, but they are different things.

• a înceta = to stop / to cease → this is the infinitive, the dictionary form
• a încetat = stopped / has stopped → this is a conjugated past form

What is happening here is:

• dictionary form: a înceta
• past participle: încetat
• full past tense: a încetat

So the sentence is built from the verb a înceta, but the form in the sentence is not the infinitive.

By itself, Muzica a încetat simply means that the music stopped / ceased. It does not say who caused it.

It could mean:

• the music ended naturally
• the music was turned off
• the performance stopped
• the sound ceased for some other reason

If you want to say clearly that someone stopped it, Romanian would usually say something more explicit, such as:

• Cineva a oprit muzica. = Someone stopped the music.

So Muzica a încetat focuses on the result, not on the person who caused it.

Yes, it is correct and natural.

That said, a înceta can sound a bit more formal, neutral, or slightly literary than some other everyday choices. Romanian speakers also often say:

• Muzica s-a oprit. = The music stopped.

That version may sound a little more conversational in many situations.

So:

• Muzica a încetat. = correct, natural, slightly more formal/neutral
• Muzica s-a oprit. = also very common, often more conversational

A rough pronunciation guide is:

MOO-zee-ka a in-cheh-TAT

More carefully:

• Muzica = /ˈmu.zi.ka/
• a = /a/
• încetat = /ɨn.t͡ʃeˈtat/

A few useful points:

• z sounds like English z
• ce in încetat sounds like che in check, but with a clearer e
• î is a specifically Romanian vowel with no exact English equivalent

Also, both a sounds are pronounced in muzica a încetat. Romanian does not usually collapse them the way fast English sometimes would.

Yes, but the given order is the most neutral one.

• Muzica a încetat. = neutral statement

Romanian can sometimes change word order for emphasis, style, or in questions. For example:

• A încetat muzica? = Did the music stop? / Has the music stopped?

But for a plain statement, Muzica a încetat is the normal choice.

To make it negative, add nu before the auxiliary:

• Muzica nu a încetat. = The music did not stop / has not stopped.

In speech and informal writing, you may also see the contracted form:

• Muzica n-a încetat.

To turn it into a yes/no question, Romanian often just uses the same word order with questioning intonation:

• Muzica a încetat? = Did the music stop?

You can also invert the order for a more explicitly question-like structure:

• A încetat muzica?

Both are possible.

Because muzica is already the subject: the music.

English might sometimes use it, but Romanian does not need a subject pronoun when the noun itself is present.

So:

• Muzica a încetat. = The music stopped.

You would only use a pronoun if you were replacing the noun in context:

• Ea a încetat. = It/She stopped
  But this is much less natural here than simply repeating muzica, because ea usually means she, and using it for things depends a lot on context.

So in this sentence, leaving out a separate pronoun is completely normal.