This page shows the location of the shanty called "Stormalong John"
You can find it on a street with tents in east Nassau:
Here is the map:
How to get[edit]
Approach it from the south and run towards it and you should catch it as soon as it begins floating away:
If you didnt catch it, leave area and try again after a few minutes when it re-appears. Or you can fast travel to the viewpoint to the NE, which will make the song sheet re-appear instantly.