Learn Hardcore Portuguese (Portugal): Esta música vai lembrar o Pedro do verão no campo. - This music will remind Pedro of the summer in the countryside.

vai lembrar = ir (to go) in the present + infinitive (lembrar).
- This is the periphrastic future (going-to future).
- It is much more common in everyday European Portuguese, especially in speech.
- It often feels a bit more immediate or conversational.
lembrará = synthetic future (single-word future tense) of lembrar.
- Correct, but in modern Portuguese (especially in Portugal), it sounds more formal or literary, and is less common in normal conversation.

So in real-life speech, people are very likely to say:

Esta música vai lembrar o Pedro do verão no campo.

rather than:

Esta música lembrará o Pedro do verão no campo.

What exactly does lembrar mean here, and how is it different from lembrar-se?

In Portuguese:

lembrar (without -se) usually means “to remind” (cause someone to remember something).
lembrar-se (de) means “to remember” (have a memory, recall something).

In your sentence:

Esta música vai lembrar o Pedro do verão no campo.
= This song will remind Pedro of the summer in the countryside.
Here, lembrar is causative: the song causes Pedro to remember.

Compare:

Lembro-me do verão no campo.
= I remember the summer in the countryside. (lembrar-se de)
Esta música lembra o Pedro do verão no campo.
= This music reminds Pedro of the summer in the countryside. (lembrar alguém de algo)

So:

lembrar-se de X → subject remembers X.
lembrar alguém de X → subject reminds someone of X.

How is the structure of lembrar o Pedro do verão working? Who remembers what?

The pattern here is:

lembrar alguém de alguma coisa
remind someone of something

So in:

Esta música vai lembrar o Pedro do verão no campo.

we have:

Esta música = subject (the thing doing the reminding)
o Pedro = direct object (the person who is reminded)
do verão no campo = complement with de (what he is reminded of)

So the meaning is:

The song will remind Pedro of the summer in the countryside.

It is not saying that Pedro remembers something by himself; rather, the music makes him remember.

Why do we use do in do verão? What is do exactly?

do is a contraction of the preposition de + the masculine singular article o:

de + o = do

The verb pattern is:

lembrar alguém de alguma coisa (remind someone of something)

Because verão is masculine and specific here (the summer in the countryside), we add the article o:

de + o verão → do verão

So:

lembrar o Pedro do verão
literally: remind Pedro of-the summer

Could we say just lembrar o Pedro de verão without the article?

You could, but it would sound odd or change the nuance.

lembrar alguém de algo with a noun without article usually feels more generic (of summer in general).
With do verão, it sounds more like a specific, known summer (for example, a particular past summer he spent in the countryside).

In practice, for a normal, natural sentence about a specific memory, speakers of European Portuguese will nearly always say:

do verão (with the article contracted into do).

Why do we say o Pedro? In English we do not say “the Pedro”.

In European Portuguese, it is very common to use the definite article before personal names:

o Pedro, a Maria, o João, a Ana, etc.

So:

Esta música vai lembrar o Pedro do verão no campo.

This is normal, especially in speech and informal writing.

Notes:

In Brazilian Portuguese, using the article with names is much less common (though it exists in some regions).
In more formal written Portuguese (like legal texts or some very formal styles), the article before names can be dropped: Pedro, Maria.

In everyday European Portuguese, saying o Pedro is completely standard.

Can we omit the article and say Esta música vai lembrar Pedro do verão no campo?

Yes, it is grammatically correct, but in European Portuguese it will often sound:

more formal, or
more written than spoken.

In everyday conversation, native speakers in Portugal are far more likely to say:

Esta música vai lembrar o Pedro do verão no campo.

than:

Esta música vai lembrar Pedro do verão no campo.

Could we say Esta música vai lembrar o verão no campo ao Pedro instead? Is that correct?

Yes, that is also grammatically correct, but it uses a slightly different structure:

lembrar algo a alguém = remind something to someone

So:

Esta música vai lembrar o verão no campo ao Pedro.
literally: This music will remind the summer in the countryside to Pedro.

However:

In practice, for “remind someone of something”, the more common pattern is:
- lembrar alguém de algo
  → Esta música vai lembrar o Pedro do verão no campo.
The version with ao Pedro sounds a bit more formal/written and is less idiomatic in everyday speech than the original.

So your original sentence is more natural.

What does no campo mean here? Is it “in the field” or “in the countryside”?

In this context, no campo means “in the countryside”, not literally a single field.

Details:

campo can mean:
- countryside / rural area (as opposed to the city)
- field, depending on context.
no is em + o:
- em + o campo → no campo
  → in the countryside

So o verão no campo is naturally understood as:

the summer in the countryside (probably a holiday, time spent away from the city).

Why is it no campo and not na campo?

Because campo is masculine:

o campo = the countryside / the field

The preposition em contracts with the article:

em + o = no
em + a = na

Since campo takes o:

em o campo → no campo

If it were a feminine noun, for example a cidade (the city):

em a cidade → na cidade (in the city)

How would we say “This song will remind him of the summer in the countryside” using a pronoun for Pedro?

Replace o Pedro with the clitic pronoun o (him), which attaches to the verb:

Esta música vai lembrá-lo do verão no campo.

Explanation:

lembrar + o → lembrá-lo (the final -r of lembrar drops and we add -lo).
In European Portuguese, with vai + infinitive, the pronoun usually attaches to the infinitive:
- vai lembrar + o → vai lembrá-lo

Other tenses:

Present: Esta música lembra-o do verão no campo.
Imperfect: Esta música lembrava-o do verão no campo.

Could we also say Esta música faz o Pedro lembrar-se do verão no campo? Is that the same?

Yes, that sentence is grammatically correct and close in meaning, but the structure is different:

fazer alguém fazer algo → “make someone do something”

So:

Esta música faz o Pedro lembrar-se do verão no campo.
literally: This song makes Pedro remember the summer in the countryside.

Differences:

vai lembrar o Pedro do verão
→ uses lembrar alguém de algo (“remind someone of something”), more direct and idiomatic.
faz o Pedro lembrar-se do verão
→ uses lembrar-se (“to remember”), with fazer as a causative verb.

Both are understandable, but for “remind someone of something”, the first structure (lembrar alguém de algo) is more natural and concise.

Can we use the present tense instead of vai lembrar? What changes?

Yes, you can say:

Esta música lembra o Pedro do verão no campo.

Difference:

vai lembrar = future (will remind), something that will happen later.
lembra = present (reminds), something that happens now or habitually.

So:

Esta música vai lembrar o Pedro do verão no campo.
→ When he hears it (in the future), it will remind him.
Esta música lembra o Pedro do verão no campo.
→ As a general fact: this song reminds Pedro of that summer (whenever he hears it).