Marketing is all about experimentation and figuring out works best for your unique product. Of course, there are always budget constraints, so if you need to choose one or the other: Both Facebook and Display ads offer unique advantages. If you are focused on finding fans and growing your music career, Facebook ads are a great way to do detailed targeting into a personal space. If you have already had success in your music career and are looking for more publicity and accolades, Display ads are a great way to get your music on the front page of major music blogs and in front of a LOT of eyeballs.
Both are great and worth testing!