Here's how to change the key signature of your music in GarageBand. Additionally, this article shows you how to change the key of some parts of your music, and not others.
In this article, I explain to you in a simple, step-by-step process, how to upload your music to SoundCloud, iTunes, and YouTube at a competitive volume.
Latency is an annoying problem to deal with, but thankfully, it's fairly straightforward to fix in most cases. Here's a list of possible solutions.