Вокальный диапазон очень важен.

In Russian, the present-tense form of to be is usually omitted.

So:

• Вокальный диапазон очень важен.
• literally: Vocal range very important
• natural English: A vocal range is very important or The vocal range is very important

Russian normally does not say есть here. Using есть in this kind of sentence would usually sound wrong or would change the meaning.

Диапазон is in the nominative singular.

It is the subject of the sentence, so nominative is exactly what you would expect.

Breakdown:

• вокальный = vocal
• диапазон = range

Together, вокальный диапазон is the subject: the vocal range.

Because it is a masculine singular nominative adjective, agreeing with диапазон, which is a masculine singular noun.

Agreement in Russian means the adjective matches the noun in:

• gender
• number
• case

Since диапазон is masculine singular nominative, the adjective also appears in masculine singular nominative:

• вокальный диапазон

If the noun changed, the adjective would change too:

• вокальная техника = vocal technique
• вокальное упражнение = vocal exercise
• вокальные данные = vocal abilities / vocal qualities

This is one of the most common learner questions.

Важен is the short form of the adjective важный.

In Russian, short-form adjectives are very often used after the subject to mean is important, is ready, is necessary, and so on.

So:

• диапазон важен = the range is important

This is more natural in standard Russian than:

• диапазон важный

The long form важный is usually used before a noun:

• важный вопрос = an important question

The short form is often used as the predicate:

• вопрос важен = the question is important

Grammatically, a native speaker may understand it, but it is usually less natural in this context.

For a simple statement like The vocal range is very important, Russian strongly prefers the short form:

• Вокальный диапазон очень важен.

Using the long form after the noun can sometimes sound:

• less standard
• more colloquial in some contexts
• or as if you are characterizing it in a slightly different way

So for learners, the safest choice here is:

• важен, not важный

Очень means very.

It modifies важен:

• важен = important
• очень важен = very important

So the structure is:

• subject: Вокальный диапазон
• adverb: очень
• predicate adjective: важен

The neutral, standard word order is:

• Вокальный диапазон очень важен.

This is a normal subject + adverb + predicate pattern.

Russian word order is flexible, though, so you may also see variations for emphasis:

• Очень важен вокальный диапазон. = It is the vocal range that is very important.
• Вокальный диапазон важен очень. = possible, but marked and much less neutral

For everyday neutral speech, stick with:

• Вокальный диапазон очень важен.

The stress is:

• вока́льный
• диапазо́н
• о́чень
• ва́жен

So the whole sentence is pronounced roughly like:

• vakaL-nyy deeapaZON O-chen VA-zhen

A more careful approximate guide:

• вока́льный = va-KAHL-nyy
• диапазо́н = dee-a-pa-ZON
• о́чень = OH-chen'
• ва́жен = VA-zhen

A useful thing to notice: unstressed о is often pronounced more like a in Russian speech.

Yes, in most contexts it does.

Вокальный диапазон is the standard way to say vocal range, especially in music, singing, and voice training.

Depending on context, Russian speakers might also say similar expressions, but вокальный диапазон is a very natural and correct term.

Since важен is a short-form adjective, it changes to match the subject.

Forms:

• masculine: важен
• feminine: важна
• neuter: важно
• plural: важны

Examples:

• Диапазон важен. = The range is important.
• Техника важна. = Technique is important.
• Упражнение важно. = The exercise is important.
• Навыки важны. = The skills are important.

This is a very useful pattern to learn, because many common Russian predicate adjectives work like this.

Yes. Диапазон is a masculine noun.

You can tell from both dictionary form and agreement:

• диапазон
• вокальный диапазон
• диапазон важен

Because it is masculine, both adjectives in your sentence take masculine forms:

• вокальный
• важен

Yes.

Russian does not have articles like a and the, so the same sentence can correspond to either:

• A vocal range is very important
• The vocal range is very important

Which one sounds best in English depends on context.

Russian leaves that distinction to context rather than marking it with articles.

Yes, absolutely.

It is a fully complete and natural Russian sentence:

• subject: Вокальный диапазон
• predicate: очень важен

Russian often expresses ideas very compactly, especially when the present-tense to be is omitted.

So although it is shorter than the English version, it is not missing anything.