Learn Hardcore Russian: По вечерам молодёжь танцует в парке под тихую музыку. - In the evenings young people dance in the park to quiet music.

По вечерам literally = “by evenings” and is a very common way to say “in the evenings / on evenings (regularly)”.
Structure: по + dative plural → вечер → dative plural вечерам.
По вечеру (dative singular) is possible but much less common and sounds more old‑fashioned / literary.
Вечерами (instrumental plural) also means “in the evenings” and is common too.
- По вечерам and вечерами are very close in meaning; по вечерам feels slightly more neutral/bookish, вечерами a bit more colloquial.

So the choice of по вечерам is just a very typical, idiomatic way to express a habitual action in the evenings.

Why does молодёжь take the singular verb танцует and not plural танцуют?

Молодёжь is a collective noun meaning “young people / youth (as a group)”.
Grammatically it is singular, feminine in Russian.
- That’s why the verb is 3rd person singular:
  - молодёжь танцует = “the youth dances / young people dance”.
Think of it like English “the youth is dancing” (when you treat “youth” as a singular group word).

So: collective meaning (many people), but grammatically singular → танцует.

What gender is молодёжь, and how do we know?

Молодёжь is feminine.
Many abstract and collective nouns ending in -ь are feminine (e.g. ночь, жизнь, любовь, молодежь).
You see its gender from how other words agree with it in different sentences:
- молодёжь была довольна (feminine past form была)
- наша молодёжь (feminine possessive наша)

In this sentence you don’t see explicit feminine agreement, but native speakers know the word as feminine singular.

What exactly does the present tense танцует mean here: “dances” or “is dancing”?

Russian present tense usually covers both English present simple and present continuous.
So молодёжь танцует can be:

“The young people dance in the evenings…” (habitual)
“The young people are dancing in the evenings…” (also habitual, in English we might still use simple: “They dance in the evenings.”)

Context (по вечерам) tells us it’s a regular, repeated action → natural English: “In the evenings the young people dance in the park to soft music.”

Why is it в парке and not в парк or на парке?

В парке = “in the park” (location, inside the park).
- в + prepositional case → парк → в парке.
В парк (accusative) would mean “into the park” (movement, direction).
На парке is basically wrong here; на is not used with парк for this meaning.

So в парке is the standard way to say “in the park” as a place where the action happens.

What does the preposition под mean in под тихую музыку? Is it “under” or “to”?

Literally под means “under”, but it has several extended meanings.
In the phrase под музыку / под тихую музыку, it means:

“to (the accompaniment of) quiet music”,
similar to English “to quiet music / with quiet music playing”.

So под тихую музыку is not “under quiet music” physically, but “accompanied by quiet music”, “to the sound of quiet music”.

Why is it под тихую музыку (accusative) and not под тихой музыкой (instrumental)?

Под can take accusative or instrumental, with a difference in meaning:

Под + instrumental → usually location: “under something” physically.
- под мостом = under the bridge (location).
Под + accusative → often direction, influence, or accompaniment.
- под музыку = “to the music / accompanied by music”.

In this context, we talk about dancing accompanied by music, so we use accusative:
под тихую музыку, not под тихой музыкой.

Why is the adjective тихую used, and how does it agree with музыку?

The base words are тихий (quiet) and музыка (music).
In под тихую музыку, музыку is feminine accusative singular (object of под).
The adjective must agree with the noun in gender, number, and case:
- Feminine, singular, accusative → тихую.

So:

nominative: тихая музыка (quiet music – as a subject)
accusative: тихую музыку (quiet music – as an object, here after под)

That’s why it’s под тихую музыку.

Could the sentence use just под музыку instead of под тихую музыку?

Yes:

По вечерам молодёжь танцует в парке под музыку.

This would mean “to music / with music” without specifying what kind of music.
Adding тихую gives extra information: the music is quiet/soft/gentle, not loud.

Does тихую музыку mean “quiet” in the sense of “low volume”, or can it mean “calm, gentle” music?

It can mean both, depending on context:

Literally, тихий = quiet, not loud.
By extension, тихая музыка is often understood as soft, gentle, calm music, not aggressive or noisy.

In many contexts, тихая музыка would be imagined as soft background music, not necessarily strictly about the volume level only.

Is there any difference between starting with По вечерам молодёжь… and Молодёжь по вечерам…?

Both word orders are correct:

По вечерам молодёжь танцует в парке…
Emphasis starts with the time frame (“In the evenings…”).
Молодёжь по вечерам танцует в парке…
Starts with who (“The young people…”), then adds when.

Russian word order is relatively flexible. Both sound natural; the first simply foregrounds the time (‘in the evenings’) a bit more.

Could we say каждый вечер молодёжь танцует… instead of по вечерам?

Yes:

Каждый вечер молодёжь танцует в парке под тихую музыку.

This means “every evening the young people dance…”.
The nuance:

По вечерам → in the evenings (generally, as a regular habit).
Каждый вечер → every single evening, sounds a bit more systematic/regular.

Both describe a habitual action, but каждый вечер can feel slightly stronger: it happens every evening, not just “typically in the evenings”.

How is молодёжь pronounced, and why is there ё instead of е?

Pronunciation: [ма-ла-ДЁЖ’], stress on the last syllable: молодЁжь.
The letter ё is always stressed and pronounced “yo”.
In everyday writing, Russians often write е instead of ё, so you might see молодежь in print, but it is still pronounced молодёжь.

The soft sign (ь) at the end softens the final consonant ж, giving that palatalized feel: not a big difference for English speakers, but it’s there in Russian phonology.