Dirigenten hører sopranen så vel som alten.

In Norwegian, the definite article is usually attached to the end of the noun.

So:

• dirigent = conductor

• dirigenten = the conductor

• sopran = soprano

• sopranen = the soprano

• alt = alto
• alten = the alto

This is one of the first big differences from English. Instead of saying a separate the, Norwegian often uses a noun ending.

Hører is the present tense of å høre.

• å høre = to hear
• hører = hear / hears / am hearing / is hearing, depending on context

Norwegian present tense does not change with the subject:

• jeg hører = I hear
• du hører = you hear
• han/hun hører = he/she hears

So in this sentence, Dirigenten hører ... means The conductor hears ...

Usually, høre means hear.

That is, it means perceiving sound with your ears, not necessarily making a deliberate effort.

Compare:

• å høre = to hear
• å lytte (til) = to listen
• å høre på = to listen to / be listening to

In a sentence like this one, hører naturally means hears. The conductor is able to hear the soprano and the alto.

Så vel som is a fixed expression meaning as well as.

It links two things together:

• sopranen så vel som alten = the soprano as well as the alto

It is a bit more formal or polished than just og.

So:

• sopranen og alten = the soprano and the alto
• sopranen så vel som alten = the soprano as well as the alto

The meaning is very similar here, but så vel som has the same flavor as English as well as.

They are definite because the sentence is talking about specific, identifiable people or voice parts.

So the idea is not just a soprano and an alto, but the soprano and the alto.

That works much like English:

• en sopran = a soprano

• sopranen = the soprano

• en alt = an alto
• alten = the alto

In musical contexts, these words can refer either to singers or to vocal parts/sections, depending on context.

The sentence has normal Norwegian main-clause word order:

Dirigenten + hører + sopranen + så vel som alten

That is:

• Dirigenten = subject
• hører = finite verb
• sopranen = object
• så vel som alten = added phrase linking another noun

So it is structurally very close to English:

The conductor hears the soprano as well as the alto.

Also, Norwegian main clauses follow the verb-second rule. In this sentence, the subject comes first, so the verb naturally comes second.

Because the noun alt takes the definite singular form alten in Bokmål.

So:

• en alt = an alto
• alten = the alto

For a learner, the simplest thing is just to learn the full pattern of each noun:

• en dirigent – dirigenten
• en sopran – sopranen
• en alt – alten

That will help more than trying to guess every ending from English.

Yes, in many situations you could say:

Dirigenten hører sopranen og alten.

That would simply mean The conductor hears the soprano and the alto.

But så vel som is not exactly the same in style:

• og = plain, neutral and
• så vel som = as well as, slightly more formal or elegant

So both are possible, but they are not identical in tone.

Not in the same structure.

Også means also / too, but it works differently in the sentence.

For example:

• Dirigenten hører også alten. = The conductor also hears the alto.

That sentence focuses on alten as an additional thing.

But så vel som directly connects the two nouns in one phrase:

• sopranen så vel som alten

So også and så vel som are related in meaning, but they are not interchangeable word-for-word.

Yes.

That is the natural interpretation. Så vel som includes both items, so the conductor hears:

• sopranen
• alten

In other words, the alto is added, not excluded. The sentence is not contrasting them; it is saying both are heard.