A estrofe vem antes do refrão.

In Portuguese, it is very common to use the definite article with nouns, even when speaking generally.

So a estrofe literally means the verse/stanza, but in context it can also mean the verse as a general part of a song.

This is more natural in Portuguese than leaving the article out.
Compare:

• A estrofe vem antes do refrão. = The verse comes before the chorus.
• Estrofe vem antes do refrão. = sounds unnatural in normal Portuguese.

Also, estrofe is a feminine noun, so the article is a.

Because do is a contraction of de + o.

After antes, Portuguese normally uses de before a noun:

• antes de o refrão → contracted to antes do refrão

This kind of contraction is very common and usually required in everyday Portuguese.

Some useful parallels:

• de + o = do
• de + a = da
• de + os = dos
• de + as = das

So antes do refrão means before the chorus.

Because when antes is followed by a noun or an infinitive, Portuguese normally uses de.

Examples:

• antes do refrão = before the chorus
• antes da aula = before class
• antes de cantar = before singing

So in your sentence:

• antes + de + o refrão → antes do refrão

This is a very common pattern to memorize: antes de.

Vem is the third-person singular form of the verb vir (to come).

Here it does not mean physical movement. It is being used to talk about sequence/order:

• A estrofe vem antes do refrão.
• literally: The verse comes before the chorus.

English also uses come this way sometimes, as in That comes later.

So here vem means something like:

• comes
• appears
• occurs

in the structure of the song.

Because the subject is singular: a estrofe.

• a estrofe vem = the verse comes
• as estrofes vêm = the verses come

This is an important distinction:

• vem = singular
• vêm = plural

Examples:

• O refrão vem depois. = The chorus comes after.
• Os refrões vêm depois das estrofes. = The choruses come after the verses.

The written accent helps distinguish them.

Usually, yes, in song-related contexts it can correspond to verse.

But there is a small nuance:

• estrofe literally means stanza
• in songs, it is often used for the verse section

So depending on context, estrofe may feel a bit more like stanza in poetry and verse in music.

Related word:

• verso = a line of poetry, not usually the whole verse section of a song

So:

• estrofe = verse/stanza
• verso = line

In songs:

• estrofe = the verse, the section whose lyrics usually change
• refrão = the chorus/refrain, the repeated part

So in the sentence:

• A estrofe vem antes do refrão.

it is describing the order of song parts.

Yes. In many contexts, refrão can be translated as either chorus or refrain.

In everyday Brazilian Portuguese, when talking about popular music, refrão is very often what English speakers would call the chorus.

In a more literary or poetic context, it can also mean refrain.

So the exact English translation depends on context, but the Portuguese word is the normal one in both cases.

Yes, the normal order here is:

• A estrofe = subject
• vem = verb
• antes do refrão = adverbial phrase of sequence

So:

• A estrofe vem antes do refrão.

That is the most neutral, standard order.

But Portuguese can also change the order for emphasis:

• Antes do refrão vem a estrofe.

This is grammatically fine, but it sounds more marked or stylistic.
For a learner, the original version is the safest pattern.

Yes, that is possible, but it is a little different in feel.

• vem antes sounds more natural when talking about the order in which parts of a song occur
• está antes sounds more like describing position or arrangement

So both can work, but:

• A estrofe vem antes do refrão. = more natural for sequence in music
• A estrofe está antes do refrão. = understandable, slightly more static/descriptive

Portuguese often uses the singular with the definite article to talk about a category or typical element.

So:

• A estrofe vem antes do refrão.

can mean the usual structural idea the verse comes before the chorus.

English can do this too, but sometimes English prefers plural more often in general statements. Portuguese is very comfortable with this singular pattern.

A rough guide:

• estrofe ≈ es-TRO-fi
• vem ≈ veng with a nasal sound, not a strong final m
• refrão ≈ heh-FROWN or heh-FRAHNG, depending on accent, with nasal ão

A few important notes:

• In many Brazilian accents, r at the start of a word sounds like an English h, so refrão begins roughly like he-
• Final m in vem nasalizes the vowel; it is not pronounced like a full English m
• ão is a very common nasal ending in Portuguese and takes practice

It can work for both, depending on context.

• In music, estrofe and refrão are very natural terms for verse and chorus
• In poetry, estrofe is also common, but refrão would only fit if there is an actual repeated refrain

So without context, many people will probably understand it as talking about the structure of a song.

Yes. It sounds natural and correct.

It is a simple, clear sentence that a Brazilian speaker could absolutely use when explaining how a song is organized.

Very similar natural sentences would be:

• O refrão vem depois da estrofe.
• A segunda estrofe vem antes da ponte.
• Na música, a estrofe vem antes do refrão.

So your original sentence is perfectly normal Brazilian Portuguese.