Watch the Training Your Inner Ear online guitar lesson by Steve Vai from Alien Guitar Secrets: Passion & Warfare
In this next segment, I'd like to talk about one of the most important things to develop in your style, and that's your ears. There's many ways you can do this, some may seem more natural than others. There's obviously listening to your favorite artists and copying the songs on the record, or getting a book and reading chords is fine too. Transcribing music - meaning the process of listening and writing down the music in manuscript form - was helpful for me, especially during my early days with Frank Zappa. It helped with my ability to translate an inner musical idea to my fingers. And that's really what it's about, or so I believe, doing so effortlessly, and without any real thought involved and just having it flow out.
To do this, you need to develop the relationship between your ears and your fingers. You want your fingers to develop eyes on them, so to speak. One great way to get started is when playing anything, especially in the beginning, take a segment of time and sing everything that you play. Now, for some it may be very simple, but some of you may be surprised how difficult it may be, as everybody has a different level of "inner ear". If you can't connect your ear with the notes that you're playing right away, don't worry, because you can develop it if you have the patience. Being able to sing what you play is going to be very helpful in identifying with an emotion or a visualization and then getting it out on the instrument in an audible way.
When you're doing your exercises or scales, it's always a good idea to sing everything you're playing. You'll know which notes are right because it will resonate with you. Put your attention deeply within a single note, sing it, and then try to find another one. You'll know when you nail it! Eventually, you can get to the point where you'll be able to sing anything you play.
There are other things you can do to develop your ears too - for example, sing a harmony (such as a 5th, or a 3rd, or maybe even a 2nd) to what you play. I used to make a tape of me playing various intervals for about an hour, followed by me saying out loud "a 5th", "major 3rd", etc. Then I'd listen back to that, hear the interval, focus on it, try to guess what it is, and then get the answer. This will advance your ability to be effective as a songwriter, soloist, and as a musician in general. Everything we go over is important, but this is vital.
I'd encourage you to conceive as many possible things as you can do to develop your inner ear. I used to take two pages of manuscript paper and just write two notes - C and D for example. I'd sing and write them out, filling both pages, and then I'd read it back. Once you have it down, add a note and sing them in your head. Continue with this, write them down, page after page, and after a while there will be nothing that you're unable to write and hear in your head. And that's liberation.