Hi there! There are a couple conditions you must meet prior to hearing sea shanties:
- You have to have visited Neketaka
- Morale needs to be higher than 30%
- Total crew size nee needs to exceed 20% of the total crew capacity of your ship
- You need to be sailing (i.e. not in combat or walking)
- They have a 40% chance of playing vs the non shanty music
My numbers might be slightly off but it's close. They react to other things too like gender ratio. If your crew is majority on gender it will change the gender of the lead singer. If it's full one gender or another, you'll only hear that one gender.
Curious to hear if you've met these conditions? Also, did you play in the beta?
There's no easy way to do this unfortunately. Unity makes it very hard to. One option would be to download fraps, open a level that has the sounds you want, turn off the voice and music in the options, and capture some footage. Then you have to convert the video to audio... Its kind of a pain :/
Justin Bell's post in Not hearing any sea shanties... was marked as the answer