Are artisits and musicians (so/that) important for the society?

Since the title is a question, it's best to include a question mark.

"that" is a little more natural than "so" here, but "so" is acceptable.

I think that musicians and artists are very important for the society.

Artisits and musicians can transmit thcommunicate situations which happen in the world through the lens of art and express the feelings of the society about the actual moment through it.

They give us new ways to describe things and life experiaences

that we can no't transmit through the words.

"can't" is most commonly used.
"cannot" is sometimes used, but it sounds pretty formal or emphatic these days
"can not" sounds even more emphasized than the above two.

Are artisits and musicians sovery important for the society?

“Artisits” is incorrect spelling. I think the word “very” sounds more natural here but it’s not incorrect. The word “the” is not needed here. A question mark is needed at the end to indicate a question.

I think that musicians and artists are very important for the society.

Again, the word “the” is not needed.

Artisits and musicians can transmit theview situations whichthat happen in the world through the lens of art and express feelings of theabout society about actual moment through it.

“Artisits” is incorrect spelling. The word “transmit” is confusing here, I think a better fitting word would be “view”. The word “which” is fine here, but I think using the word “that” sounds more natural. I don’t understand what you’re trying to say at the end (last 5 words).

They give us new ways to describe things and life experiaences

It should be “experiences”.

that we can not transmit through the words.

Adding the word “that” is not necessary but I think it sounds more natural

Are artisits and musicians (really) so important for the society?

When "so" is used in a question it sounds like it's questioning someone's opinion or questioning a general conception held by society. Because you used "so," the first line of the following interaction is implied:
Society: "Artists and musicians are important for society."
You: "Are they really so important for society?"
Commonly, "really" is added as well to emphasize that you're asking about something's qualities "in actuality" rather than "in theory"

I think that musicians and artists are very important for the society.

Artisits and musicians can transmitdepict/communicate the situations whichthat happen in the world through the lens of art and express the feelings of their society abouties at the actual moment through itey are going through those situations.

"depict": focuses on the turning the information into art form
"communicate": focuses on relaying the information
I think both "the situations" and "situations" can work. "the situations" brings to mind very well known events, like the World Wars, Tiananmen Square massacre, etc, while "situations" can be anything

They give us new ways to describe things and life experiaences

that we can not transmitconvey through the words.

"transmit" is really only used for technological communications, like "transmitting a radio signal"

Are artisits and musicians so important for the(really) necessary in society?

I think that musicians and artists are very important for the society.

Artisits and musicians can transmit theconvey situations which happen in the world through the lens of art, and express feelingsin doing so express the spirit of thea society about actual moment through itt any given moment in time.

I think I edited this sentence quite a bit, but I just wanted to make it a bit polished and natural-sounding. Hopefully it still conveys what you wanted to say.

They give us new ways to describe things and life experiaences in life.

wWe can not transmit through the words(always) convey through speech (that which can be conveyed through music).

Are artisits and musicians so important for the society?

No need for "the" since you are talking about society in general/the concept of society, rather than one specific society.

I think that musicians and artists are very important for the society.

Artisits and musicians can transmit theportray situations which happen in the world through the lens of art, and express the feelings of the society about actualthose moment through its.

Situations in general, rather than specific situations.
Examples --> people hated the fireworks last night vs people hate fireworks (in general).

They give us new ways to describe things and life experiaences

Things and experiences seems a bit redundant, so I cut it down to just experiences.

that we can not transmit through the words.

I have linked this to the previous sentence with "that".