Hi,

No, you don’t have to know music theory in order to make music. It is even possible to learn how to play from someone who also doesn’t know music theory (the majority of “teachers” on the internet)!
But eventually, at the very end of that chain of “theory-dumb” teachers and instructors, you will find someone who does know!

The “rules” of music theory are guidelines much more than they are rules. They are based on the observation of what successful composers have been doing over the centuries, and they form a consensus on what will typically sound good. But you are always free to break the rules if you think that doing so will make you sound better.
Theory is there only to help you understand better what is going on (so you remember it more easily, perhaps) and to offer you a broader palette of possibilities. Believe me: the more theory you know, the easier it will be to compose interesting melodies, progressions, cadences and chord borrowings!

Going from an E major chord to an E minor chord can work in many circumstances and theory has you covered. But maybe you can make it work in circumstances that are not directly covered by the theory. Great! Do it, then!

Playing by ear is in no way contradictory with knowing theory. When I am improvising, I am in no way referring to music theory. As someone put it (can’t remember who), I am actually “trying to get my brain out of the way as much as possible”! The theoretical work happened before the improvisation, when I analyzed the piece of music and decided what improv strategy would work best.

Albert Einstein was a genius physicist with extraordinary intuition. In his mind, he had a clear picture of the interplay between spacetime and geometry. But his mathematical background was (originally) not very strong. So he collaborated with and learned from Gregorio Ricci which enabled him to formulate his ideas in the formalism of tensor calculus. He learned theory so he could write down the theory of General Relativity.
Imagine what Jimi Hendrix could have done if he had known some music theory! 😉

Biagio,
I never understand the idea that learning theory somehow hampers creativity or gets in the way of your playing.
The more I progress in understanding theory the easier it is for me to learn songs and solos and to see what’s possible, and to repeat what I’ve discovered.
If I can pick out the key I can usually figure out the progression by theory and hear when chords are out of key or when the song switches to the relative key.
When I can see chord shapes and relate harmonized sixths and thirds and represent chords with diads, it helps my soloing and rhythm playing.
When I can see that the riffs in the rhythm part of Sultan’s of Swing are all A major pentatonic arpeggios or that David Gilmour is manipulating pentatonics with bent notes, ie a 2 1/2 note bend from the b7 to the root to the minor 3rd, I can reproduce it.
If I can see intervals around a dominant chord I can learn to manipulate sounds between the major and minor pentatonic.
If I understand secondary dominants and ii-V-1 and diminished substitutions I can really embellish a 12 bar blues.
If I understand modes I can colour my pentatonics in a more interesting way.
I can’t comprehend why you wouldn’t want to learn at least some basic theory. I’m not Jimi Hendrix. I think not learning theory would ultimately hold me back.
I agree that your brain can’t be thinking about theory when you’re playing. I think you have to learn it well enough so that you can put it aside.
John

I once knew a guy who could sit down at a piano and play any song you could name….as long as he had heard it before. He had zero training in music, never had any piano lessons, and had zero knowledge of music theory. I’ve always wondered how he was able to do it. And I’m pretty sure many of the best guitar players have a similar skill, whatever it is.

This discussion is always interesting to me. “Playing by ear” is HARD!! Look at that fretboard and tell me where to start to solo over the chord progression that’s playing. I’d poke around for hours before finding a “Mary Had a Little Lamb” caliber melody that worked… and it would suck as anything anyone would want to listen to. Yes, there are some great players who have great ears and learned by ear, and most likely in the company of other great players who learned by ear, or via an oral tradition of passing along tips and licks. And that tradition, though they may not have realized it, was passing along theory, perhaps by other names. If you’ve learned the shape of an E chord or a D chord, you’ve learned some theory. I’m sure there was the odd musical prodigy who picked up a guitar without ever seeing one before and just found a workable and pleasing technique, but for the rest of us, theory will only help when accompanied by practice and developing our ear. And, there’s the other side of this where one knows tons of theory but can’t play a song to save their life.

Not to be too cynical, but quite often when someone talks about playing by ear and not worrying about theory, it sounds like an excuse to avoid putting in the time and work. For every hour I’ve spent with the guitar, Hendrix probably spent 100 hours. You discover things as you experiment and how you see the instrument changes and grows. The theory may not be necessary, but it does speed this process significantly.

Michael L wrote:

“Playing by ear” is HARD!!

Playing by ear is hard but it can be learned.

If you ever take a harmony and composition course in a classical academy or conservatory, you will probably be requested to do an exercise called “continuous bass” (aka “basso continuo”). Basically, you are given a bass line with indications regarding the inversions that are supposed to be played over each bass note, and you are supposed to improvise two or three melodic lines on top of the bass, by ear! It’s difficult, but the more you do it, the better you become (or the less you suck, depending! 😉 ).
During the Baroque period, the continuous bass system was actually used as a cheat sheet: instead of writing down the full score, musicians only notated the bass and the chord inversions they wanted on top of that. Nowadays it is used as a painful and difficult (but rewarding) exercise to develop your ear.

There are always many ways to realize a continuous bass – some better than others.
The focus in this exercise is actually much more on the melodies developed by the different voices than on the chords; it’s all about voice leading. After having practiced this exercise many times, you tend you develop a natural ability at identifying the best sounding paths for the voices within the chords.

This in turn naturally leads to a bunch of theoretical “rules” regarding the way chords should progress. But these rules are simply a collection of best practices, as I already mentioned. You are always free to do it your own way.
When you then sit down and write out your composition, you sort of “hear” what it will sound like, simply because you have developed that internal ear.

I don’t see much attention being given to voice leading and melody on YouTube. The vast majority of guitarists tend to focus on strummed harmony (chords) exclusively.
The only form of ear training consists in musical dictations; but as has been said already in other threads on this site, there is a huge difference between hearing intervals of a single melody and hearing the same thing in the context of chords!

Of course, probably none of us are Stevie Ray lol