[N-lightMike]

Hello @Mark-J ;

So, the direct answer to your questions:

I’ll answer the second one first as the answer is simple: No. You don’t need to learn all new chord shapes.

Now, the explanation is the answer to the first question: “what is the purpose”. The purpose is to have the strings tuned to a chord. You get a chord when you simply strum or pick without fretting. This opens up a lot of techniques that can’t be done with standard tuning. It also makes “normal” playing easier because you can make such extensive use of open strings.

The power and uniqueness of open tunings will become obvious once you get into them and start learning.

I hope this helps.

MG 😀