1. Making music the hard way - get a bunch of musicians together & start playing with all the pros & cons that comes with it.

2. Easier way - birth of the arranger. Control your band under your finger tips with all it's pros & cons.

3. Latest trend - Have access to the worlds best musicians and arrange to your hearts content.

4. AI - I predict that this will be expanded enormously in future.

For 3:

1. You have to be computer literate.

2. You have to be super creative as you are putting your band with their skills together - choices literally thousand times more than with any arranger so you need to know what you want.

3. You must know music - music theory might even help.