I'm kinda new to music theory.

I am always told that to play songs on, for example, a piano I should:

  • know which key is responsible for which note.
  • adapt my ears to notes, so that I know which note I should play to produce the right sound in a piece of music.

And I am always told that knowing music theory is necessary for those who want to:

  • read music from a sheet.
  • be a composer.

I know it's better to know music theory for those who just want to play songs they hear on, for example, radio. My question is that is it necessary here?

  • You don’t have to do anything you don’t want to do. Will studying music theory help you understand music? Absolutely. So the question for you is, how well do you want to understand music? Commented Nov 18, 2021 at 16:08
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    Welcome! I'm afraid that, as it stands, this question is subjective and likely to get opinion-based answers, which is not covered here. As the linked page suggests, you could edit it into a question that will get better answers, perhaps by focusing on how theory might help in reading and composing. Good answers would be more than the binary "yes, it's necessary" or "no, it isn't." Commented Nov 18, 2021 at 16:16
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    Fair enough. The answer also hinges on what "counts" as music theory. We tend to think of it as the analysis of the chords and patterns that make up a piece. Is this necessary to simply read sheet music? No. But if you count knowing the difference between a quarter note and half note, understanding sharps and flats, or reading key and time signatures as "music theory" then yes, these are necessary. Commented Nov 18, 2021 at 21:25
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    I'm voting to close the question because it needs more details. What is specifically the theory you consider to learn or not? When you learn to play an instrument you inevitably learn some theory. If you don't learn it from someone else, you end up figuring it out by yourself. What is your dilemma? Are you worried about the time you need to devote to learning theory, or perhaps you don't know how to apply some theory you learned doesn't apply to the music you know, or is it something else? Commented Nov 19, 2021 at 4:43
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    Technical proficiency is the only thing you need to do covers. So what's necessary is ten thousand hours of practice. For improvisation you've either 'got it' or you don't, if you don't then I'd assume theory would help immensely with faking it.
    – Mazura
    Commented Nov 19, 2021 at 17:34

8 Answers 8


tldr; there is a commensurate level of theoretical knowledge that will help immensely with what you want to do. It may not be much theory, but if you know it, you'll be much better off (unless you're a musical genius, as Michael Curtis points out).

When someone with extensive theory knowledge listens to a song, they might think, e.g., "Oh, that's a I-vi-IV-V progression in G." Thanks to their theoretical knowledge, they've recognized the pattern more quickly, they've expended less mental effort, and they'll remember that song for a longer time.

You can probably already see how theory helps. When you play by ear, you're decoding sounds into notes. Theory provides structures and frameworks for conceptualizing both of those things (the sounds and the notes). Theory identifies patterns in music. It's like the teacher standing over your shoulder saying "look at the chords you just played--it's the same sequence as the song you learned two weeks ago." When you spend time thinking about those patterns, learning them, and naming them, you will be faster at identifying them and better at remembering them. Knowing those patterns is essentially a "shortcut" that reduces the required mental effort.

In essence, when you learn a song off the radio instead of reading sheet music, you're transcribing. The less intensive your transcription work, the less theory you'll require. If your desired task is to play melodies and chords, then you don't need to go buy 10 books on theory. Focus on diatonic chord progressions and the major/minor scales, and that will probably be enough.

On the other hand (to use a more extreme example), if you want to transcribe exact chords/notes on a solo jazz piano track, then you'll want to know a wide range of theoretical voicings (upper structure triads, combination triads, quartal voicings, stacked thirds, drop-2, shell voicings, type A/B voicings, etc. etc. etc.).

Theory is nothing more than a collection of statements describing patterns in the music. Knowing those patterns helps. But you only need to study the patterns you care about.

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    The theory also gives you creative license and technical know-how to fill in parts that you did not perfectly replicate. Most people know the song "Amazing Grace", but if you know the theory behind harmony, you don't have to memorize the base lines and just make it up as you go along.
    – Nelson
    Commented Nov 19, 2021 at 2:48
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    Knowing the language is a communication tool – even with yourself. E.g. many popular songs can be entirely described by something like "It's a 4-chord-song in D with an ABACAB form and half-step modulation at the end." If you know the language (and music is a language), then that is literally you need to know to play that song, at least in a basic version. Commented Nov 19, 2021 at 13:48
  • I've actually found the opposite when it comes to my transcribing (admittedly rock- and metal-leaning) video game music: the more intensive my transcription, the more I actually need to throw my existing theory knowledge out the window. I've ended up transcribing some key ambiguity and rapid-fire key changes in my most difficult transcriptions, and solos tend to refuse to fit cleanly in any meter and go MIDI-style instead. (On another note, the latest piece I transcribed the melody of spammed a Cm-Em-Cm-Em chord progression, so time to throw determining a key out the window.)
    – Dekkadeci
    Commented Nov 19, 2021 at 14:03
  • @Dekkadeci, that's a great example. So, I think the point I was attempting to make is that the patterns still exist, but just become more complex. Classical harmony of course won't be the relevant theory to help with super complex video game/rock-metal music, because the harmonic structures and patterns are different. I know enough about those genres to appreciate the incredible complexity that can be involved, but not enough to be able to describe the relevant patterns intelligently.
    – jdjazz
    Commented Nov 19, 2021 at 16:56

Necessary? No.

Helpful? Yes.

You can compare it to just about any other endeavor. The more you know about the concepts and terminology of any given field, the more effective you will be in the study.

Being illiterate in any topic is not a benefit.

Some like to cherry pick examples of the supposedly unstudied geniuses, like Einstein failed math, Bill Gates dropped out of college, and the Beatles couldn't read music, as justification for avoiding any study. The problem with that is: extraordinary examples don't make the norm, those examples are often untrue, those examples overlook the people gained the same studied knowledge through non-traditional paths, and copying one characteristic will not give you the whole package. Not learning to read music will not make you as good a musician as The Beatles.

Is knowing music theory really necessary for those who just want to play songs they hear?

Most likely it will be helpful. Don't use the word "necessary" to load the question. Of course it isn't necessary. There is no question of requirement. The question is whether it is beneficial.

Someone may have a talent for playing by ear and have honed their skill at it through practice. They will know things about how music works... and probably give their own idiosyncratic names to things. Their skill is a combination of ear training and pattern recognition via a personal path.

If that doesn't "just happen for you" then the traditional course of ear training and theory study will help you. It will help you, because it will teach you to hear musical patterns and understand their practical application.

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    Not to mention that these geniuses stories are often untrue or exagerated, for example Einstein being bad at maths is most probably untrue
    – Kaddath
    Commented Nov 19, 2021 at 8:23
  • ...indeed these stories are often suggesting quite the opposite of what's really going on. Geniuses often perform worse than one might expect at school because they're already too good at the theory, have already read the deep literature on their own and don't see the point for wasting more time with silly exercises on a level they have long passed. (Then again, of course there are also people who think they know all the theory, but actually have huge gaps in their knowledge...) Commented Nov 19, 2021 at 11:55
  • Genius is a tricky word often with poorly defined meaning because we attribute it to so many different things (being a savant, achieving greatness). Someone can be a genius in one field and not another. Einstein was better than most at math but not a mathematical genius--he got help with general relativity from mathematical geniuses like Emmy Noether and David Hilbert. Marcel Grossman pointed out to Einstein that he should use Riemann geometry. Einstein's genius lied elsewhere, in perceiving the deep structures of the universe (light is quantized, gravity is the warping of space-time, etc.).
    – jdjazz
    Commented Nov 19, 2021 at 13:35
  • Musical savants do exist (and our advice may not apply to them). But they probably don't post questions on this site.
    – jdjazz
    Commented Nov 19, 2021 at 13:35
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    From what I've read, Bill Gates dropped out of college in order to focus more on Microsoft.
    – Dekkadeci
    Commented Nov 19, 2021 at 14:10

Yes, you are allowed to play piano without any knowledge of notation or any other 'theory'. There have been some very accomplished players who were completely untutored.

They learned, by trial-and-error, what notes made what sounds. They began to recognise patterns, so that what they'd worked out for one song could make it quicker to work out the next one. They were developing a concept of 'theory'.

It can be a heck of a lot easier to read a book than to wait until someone else decides to recite that story and try to remember it. Same with music. 'Really necessary'? No.


Clearly you can do whatever you want to do. You could try to learn a bunch of theory all at once, which wouldn't be very much fun for you. But if you buckle down and study hard it won't be long and you'll start to see things make more sense for you. You would be working on very simple music, which might frustrate you. Are you that patient? If you are, this method pays big dividends down the road.

Or, you could just keep on doing what you're doing if it is enjoyable. Music was never meant to be a chore. The day may come when you discover something that you really, really WANT to understand. Then, you can dig in and learn that thing you really want to know and theory will be just as enjoyable as playing.

My advice, find a private teacher you like. Tell him/her where you're coming from and let then teach you piano and they'll naturally weave in theory as you go.


Why do people think western music tradition requires you to learn music theory if it is not necessary? Do people think musicians enjoy exercises in futility? It is taught because it improves every part of your musicianship. Why do people have such a hard time believing this? Do these people also go to Harvard and question why the chemistry department requires you to learn theory and practice or why you cannot graduate a maths degree by doing algebra and not trigonometry?

People think that a great teacher and hard work leads to great musical ability. This is certainly a big part of it but the part that is not discussed nearly often enough is the crucial part that an early, quality music theory education plays in producing musicians of the highest order.

In closing this question is analogous to asking can a blind person find the entrance to your house if he gets to your house? Given enough time and effort, yes. An easier solution would be for the blind person just to be able to see the entrance of your house.

Can you figure out V - I is a good way to end a passage, sure. That is how this piece of knowledge was accrued originally all those centuries ago. It would be easier for someone just to tell you that give you a couple of examples. Show you it is the case and you to go on your merry way.

  • I love studying theory and find it extremely useful. You asked "Why do people think Western music tradition requires you to learn music theory if it is not necessary?" From my interactions, I think some such people view theory as a form of intellectual elitism. It's a gate that keeps out those without the formal education. If there's any truth in that metaphoric gate, then this is a substantial fact to reckon with since many people in music don't have formal education, particularly in non-classical genres.
    – jdjazz
    Commented Nov 20, 2021 at 17:45
  • In total fairness, I can see where that misperception comes from that theory = elitism / gatekeeping. Sometimes theoreticians convey the belief that (a) music can't be fully enjoyed without understanding the theory, or (b) music is inferior if it can be enjoyed without understanding the theory. We don't get a ton of questions on this site about rap or heavy metal, for example, and I don't think that's a coincidence--it conveys something about the established relationship between those genres and theory.
    – jdjazz
    Commented Nov 20, 2021 at 17:48
  • And a couple of times, those musical forms have been disparaged on this site. (I remember one instance where a very well-established, highly visible community member called the music "noise" and questioned why someone would attempt to analyze it, rhythmically.)
    – jdjazz
    Commented Nov 20, 2021 at 17:49
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    I'm with jdjazz here. 'Theory' is often seen to be for elitists - particularly, I've found, amongst guitarists, self-taught ones especially. Several of the guitarists I play with overtly imply that theory is not for them - even with offers of free explanations (!). It doesn't stop them being good players in their own right. It does however stop them being able to speak in a language which a lot of us do understand. It also slows down the rate of learning new material - of that I'm certain. But, as a necessity - no, it's more of a bonus - for those who see the benefit. Not all players, sadly.
    – Tim
    Commented Nov 21, 2021 at 13:52
  • I don't really understand why people refuse an education. I taught 9 year old this for 5 and a half pecans a month. There really is no reason why anyone cannot learn this subject at a reasonable level.
    – Neil Meyer
    Commented Nov 21, 2021 at 13:56

A decent percentage of people will just be unable to "play by ear". (Possibly they are deaf, or tone deaf, or just bad at it like me.) For those people, reading some kind of widely available written notation is the most practical way of learning new music, usually sheet music or possibly guitar tablature. But you only need mechanical knowledge of the notation for that--this shape in this position means play this note for this long, this word means play louder, this symbol means play the same section over again, etc.

The alternative for us tonally challenged folks would be some kind of verbal/visual training, but even in these times just learning to read sheet music is a lot easier than trying to find a tutorial for every song you want to play. (Not to mention faster and more convenient.)


Most of the time I listen to music I'm consciously hearing the scale degrees 1-7 (I-VII) along with some non-scale tones. I play by ear on alto recorder. I hear the piece and where it lies on the scale, then i play it in one of the two keys I'm best at and that give the best range and comfortable playing. I almost never play things in the original key, but rely on knowing where in the scale its happening. A short section of music by itself can qualify as two different keys; playing major scale you may end up in minor for a little bit (in question). Knowing these overlaps can save you headaches as a by-ear player. In minor and major, notes 4-5-6 in one key is 1-2-3 in another key. I always stumble on this.

+1 jdjazz answer!

Music theory and composing: We could go off about this but its not what you asked :D

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    Scale degrees are indeed 1-7. I-vii(o) are usually used for triads (chords).
    – Tim
    Commented Nov 21, 2021 at 13:56

Everyone is pretty much free to reinvent the wheel.

That said, a lot of basic "wheels" in the music theory are rather easy to reinvent. I know because I did.

Other things are pretty much easier to read somewhere.

Q: "Do I need to be an engineer in order to hang a picture on the wall" ?

A: "Not really. But it helps a great deal."

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