Making music is inherently a collaborative process, as everybody needs somebody else. You may be the best guitar player in the world, but you may not know anything about engineering, mastering, or even about writing the perfect hook on your next single. Finding that right person can be a challenge, but it isn't impossible. If you're in the market for a fellow musician, songwriter, or music professional to work with and create some kickass art with, here are a few new services you'll definitely want to check out. Best of all, all five of these are free to join, so you've got nothing to lose!