So much of rock guitar playing has to do with the tone and the attitude you're using, so let's start with the tone. I'm using my Fender Stratocaster for this tutorial, but you can use any guitar for the examples. I'm using my bridge pickup to get an aggressive sound.
First we'll go straight into the amp with a clean tone. I have the gain set to 3 out of 10 in order to get a tone that is nice, clean, and pretty. Check out what happens when we turn the gain all the way up - you'll immediately notice that it gets louder. In order to keep the volume the same and just change the sound, we'll turn down the master volume simultaneously. You'll notice that it's now "breaking up", meaning overdriven or distorted.
Originally, amps didn't have both master volume and gain; they only had a volume control, and when you turned it up really loud it would distort. But that's inconvenient, so people started using a master volume to compensate, or used overdrive pedals to simulate the sound of the amp breaking up.
It's important to note that the more of this overdrive effect you add, the more your voicings will start sounding cluttered and messy. This means you'll have to adapt your voicings to work well with this tone, and that's what I'll show you in the following lessons.