The sound of violin

Day 1. We are the twelfth June 1728. I am John Newgate and I am a pirate. Today I leave Seaerpool in board of a biggest pirate ship. The ship is enormous and it have black sails. On the bow of the ship there is a skeletons of a narwal not really young, on the stern, the wood is sculpt like the architectural of a mansion. The wood of the ship look like a grilled steak. Inside the boat spiderweb reign. I am the navigator on board and my captain is Edward Rocker a famous pirate and the rest of the crew. In all we are 33.
Edward is my friend since our childhood and since then we have never moved away. 2 month ago, we find a treasure map who indicates the treasure of Morgan Low a famous pirate of the XVIIe century. He hides his treasure in the Cap of bad hope in South Asia.
But the only ship that we found is the Narwhalo : a legendary hunted ship. The legend say that when we don't see the firm ground, in a moment of the day or the night we can hear a sound of violin during 3 minutes and 58 seconds who come from of the deck of the ship. You must never look the player of violin. Why ? Nobody know...

Day 2 : We are the thirdteenth June 1728. The night was calm but I think that the day will must be long... The crew is stress less because of the foam, Sharrt, spread rumors. He always afraid the crew with his stories of the ship for kids. Anyway, this afternoon I search a violin hide on the boat, we are never too sure but I don't find the musical instrument.

Day 3 : We are the fourteenth June 1728. Now no more island on the horizon but the crew is now use to lives in the Narwhalo and since I did not find the violin, no one believes on the legend. It just a legend for frightening children.

Day 4 : We are the fifteenth June 1728. The ship is calm today, ours foam, Sharrt must still sleep. 2 hours later, Sharrt is not finding. I thank that he played to hide and seek but when I and the rest of the crew hear the violin, we understand than the legend is real. The player of violin is on the deck but fourteen members of the crew too. 3 minutes and 58 seconds later the sound disappear. Me and Edward run to the deck but no one is there... everybody disappear.

Day 5 : We are the sixteenth June 1728. Nobody close them eyes this night. Normally after 15 members disappear... Now we know that the legend is real so if we follow the legend, it say that the freak appears just on the deck so we limit the passage one the deck. It the only things that we do now...  The sound was at 3pm and nobody was on the deck at the moment but we must be careful.

Day 6 : We are the seventeenth June 1728. Today Edward and me have point out that we divert of our trajectory. So inside the boat we draw a new trajectory when we hear the violin. But today a thing wrong. The sound was not on the deck : he is inside the ship. The legend is fake.
Edward protect me... The freak got him and 6 other members of our crew... We have not captain now. I think we are all dead. We had not leave Seaerpool with this cursed boat. The rest of the crew is depress, we are in danger everywhere on board.

Day 7 : We are the eighteenth June 1728. I am on the deck and I tidy up the mainsail sheets. It is at this moment that I heard. The violin ! He is just in my back. If I turn around, I disappear, I must keep my once control, close my eyes, sit down and wait the sound stop. I am sit since 2 minutes but the sound... stopped. The music lasts 4 minutes not 2. Why the violin stop why the freak stop to play violin ? So I keep my courage and open my eyes... He looks me... the freak...
And that is how John Newate disappears too. You must never look me !