The story of the dramatis personae is so sad and music, with the voice of the sea, fully takes him, letting him forget everything, including the pain( and fucking the regulations), so brings him the happiness.

I'm still trying to sort this sentence out. I suppose that him refers to a particular character in the film, say the pianist. Here's my attempt:

The story of main character is a sad and musical one. The sound of the ocean engages him fully, letting him forget everything, including his pain and his damn the rules attitude, and makes him happy.

I may have misunderstood what you were trying to say.

When you know what music brings to him, you begin to appreciate what the music means to us. So you begin to close your eyes and attempt to taste what's in it. You find it so touching, so open up your heart and let it sink down to the bottom of your body.

When you realize what music brings to him, you begin to appreciate what it means to us. You begin by closing your eyes and attempting to savor its ingredients. You find it so touching that you open up your heart and let it sink down to the bottom of your soul.

He doesn't want to get onto the land for he just doesn't like it and fears it so much so that he sinks with the ship which is scrapped by being exploded.

The pianist does want to go back on land because he just does not like it, and he fears it so that that he goes down with the ship when it is scuttled.

The music he has every played, which has moved the hearts of everybody who has listenned to it and who loves the sea, disappears too, except one record, which he has refused to give to the publisher and thrown into the trash can but later has been recovered by one of his pal.

The music, which he has always played and which has moved the hearts of those who have listened to it and who have loved the sea, disappears with him, except one recording which he has refused to give to his publisher and thrown into the trash where it is later recovered by one of his pals.

With the record, we could sink ourselfs into music, and travel to the sea. Maybe when you listen to the sea, you can hear the voice of the sea, in which is mixed his music drifted from the ship wreckage at the bottom of the sea.

With this record, we can immerse ourselves in his music and travel to the ocean. Maybe when you listen to the sea, you will hear its voice in which is mixed his music drifting up from the wreckage at the bottom of the ocean.

Hope this helps, and maybe others will have suggestions, too.

Ceci n'est pas un seing.