Working with people, the musical part is one thing but the personal part is totally different and just as critical. If the friendship is there and it's a lasting friendship, then it will take care of itself.

This quote is saying that it is important to have a good friendship with someone you collaborate with. Music is an important factor when working together, but just as important is having a solid relationship built on trust, respect, and friendship. When this friendship is real and lasting, it will help to make the collaboration easier and more enjoyable.