На репетиции солист два раза повторил припев, а потом начал первый куплет.

На репетиции is the normal Russian way to say at rehearsal or during the rehearsal/rehearsal session.

With events, activities, and organized gatherings, Russian often uses на rather than в:

• на концерте = at the concert
• на уроке = in class / at the lesson
• на встрече = at the meeting
• на репетиции = at rehearsal

Here репетиции is in the prepositional case because it follows на in a location/time setting.

The base form is репетиция. After на when it means location or situation, Russian uses the prepositional case:

• репетиция → на репетиции

This is a very common pattern for feminine nouns ending in -ия:

• лекция → на лекции
• станция → на станции
• репетиция → на репетиции

So the ending -и here shows the prepositional singular.

Russian has no articles, so there is no direct equivalent of the or a/an.

So солист can mean:

• the soloist
• a soloist

Which one is meant depends on context. In your sentence, English would naturally say the soloist, but Russian simply says солист.

Yes, два раза and дважды can both mean twice.

• два раза = literally two times
• дважды = twice

In everyday speech, два раза is very common and sounds natural.
Дважды is also correct, but can sound a bit more compact or slightly more formal depending on context.

So these would both work:

• Солист два раза повторил припев.
• Солист дважды повторил припев.

Повторил is perfective past, which presents the action as completed: he repeated it, and that action is finished.

In this sentence, the sequence is important:

1. he repeated the chorus twice
2. then he started the first verse

That is why повторил works well.

Compare:

• повторил = repeated (completed action)
• повторял = was repeating / used to repeat / repeated in a process-like sense

If you said повторял, it would focus more on the process or ongoing action rather than the finished result.

For the same reason: начал is perfective past, showing a specific completed event in the story line — then he started the first verse.

• начал = started
• начинал = was starting / used to start / started repeatedly or as background information

Because the sentence narrates a clear sequence of finished actions, начал is the natural choice.

Yes. Припев is the direct object of повторил, so it is in the accusative case.

However, припев is a masculine inanimate noun, and for masculine inanimate nouns, the accusative singular is often the same as the nominative singular.

So:

• nominative: припев
• accusative: припев

That is why the form does not visibly change.

Because куплет is also a direct object after начал, so it is in the accusative case.

Again, куплет is masculine inanimate, so:

• nominative: первый куплет
• accusative: первый куплет

Both the adjective and noun stay in the same form as the nominative here.

Compare with an animate masculine noun, where accusative would change:

• я вижу нового солиста = I see the new soloist

But with an inanimate noun:

• я начал первый куплет = I started the first verse

Both а and и can sometimes be translated as and, but they are not identical.

Here а потом is very natural because it marks a transition to the next step:

• first he did one thing,
• and then / then he did another.

So:

• а потом = and then / then
• и потом is possible in some contexts, but here а потом sounds more natural for moving the story forward.

Think of а as a connector that often introduces a new step, contrast, or shift.

Russian word order is fairly flexible, though not completely free. The sentence you have is neutral and natural:

На репетиции солист два раза повторил припев, а потом начал первый куплет.

Other orders are possible, for example:

• Солист на репетиции два раза повторил припев, а потом начал первый куплет.
• Два раза солист повторил припев на репетиции, а потом начал первый куплет.

But changing the order changes emphasis:

• sentence-initial На репетиции highlights the setting
• sentence-initial Солист highlights the person
• sentence-initial Два раза highlights the number of repetitions

So the original version is good, standard narrative Russian.

These are common song-related terms:

• припев = chorus
• куплет = verse

So the sentence describes song structure:

• he repeated the chorus
• then started the first verse

This may feel reversed if you are thinking of a typical song order, but grammatically it is completely fine.

Yes. Начать can be used with a direct object in Russian.

Examples:

• начать урок = to begin the lesson
• начать разговор = to start the conversation
• начать песню = to start the song
• начать первый куплет = to start the first verse

So начал первый куплет is perfectly normal Russian.

It can suggest either, depending on context.

• at rehearsal = location/situation
• during rehearsal = time frame

Russian на репетиции naturally covers both ideas. English may choose one or the other depending on style, but Russian does not need to separate them here.