Why is it that I can sometimes guess the next note?

For some songs and musical pieces that I am listening to for the first time, why is it that I can occasionally guess what the next note will be? I imagine the next note in my head and sometimes it is exactly correct.

I find that this happens more often for slow piano pieces - but occasionally for other kinds of music. Is there some kind of musical theory that somewhat determines what the next note can/should be to make the piece sound good?

And sometimes I also imagine two possible notes, and one of them is correct.

I play the drums and guitar but I'm not very good, and I have limited musical knowledge outside of those instruments. So it's quite an odd experience for me.

Edit: for the sake of completeness, the piano piece I listened to before asking the question was ‘Low Mist var 1 day 1’ by Ludovico Einaudi. And the note that I anticipated was the 4th.

• Confirmation bias is also bound to make it seem like this happens more often than it does – mowwwalker Mar 21 '19 at 23:53
• Any guessing task will produce occasional hits due to sheer chance. When you get more hits than chance would explain, then it's time to wonder about hidden regularities. – Kilian Foth Mar 22 '19 at 7:17
• Although I wouldn't discount the ability of the music to "lead" a listener to the correct note, or at least narrow the field of possibilities. – user45266 Mar 22 '19 at 15:17

First off, for any melody that stays within a key, you have about a 1/7 chance of any random note you guess being the next note.

Second, there are popular melody patterns and techniques, and sometimes the chords being played will suggest likely places for the melody to go. Depending on the chords and the harmony, you may be instinctively understanding that a chord tone is likely, and that brings the probability of a randomly guessed chord tone being right down to 1/3 or 1/4.

This is one way that it's possible for people with no knowledge of music theory to make up their own melodies to hum that sound "good" (at least to them). They are basically guessing what the next note could/should be based on their tonal memory of music that they like and the popular melodic patterns and elements used in that music.

• Even reducing your guesses to 1/7 is, in fact, making inferences about the following (unknown) notes. Technically, there is no guarantee that the next note will be in key, and yet, at rates much higher than chance, you can expect the next note to be in key. That is a non-perfect guess in itself. (You can then extend this argument to saying that it's likely one of 12 notes, and then you can go beyond this system, and so on...) – Eff Mar 22 '19 at 9:39
• Music theory offers a couple of benefits over innate musical sense: (1) it allows people who have not developed innate musical sense to write music that will fit the expectations of people who have; (2) it doesn't get personally invested in any particular piece of music. A composer who's been working with a piece of music for awhile may become accustomed to how it goes, and not be able to reliably judge how anyone else would perceive it. Music-theory predictions of how people would perceive music would be unaffected by such things. – supercat Mar 22 '19 at 15:18
• Even nonmusical audiences can usually guess the next note if you play an ascending major scale and then ask them for the next note, the octave. +1 – user45266 Mar 22 '19 at 15:20
• Basically, your brain is doing the same thing your phone does when it tries to predict your next word before you start typing it. – Arcanist Lupus Mar 22 '19 at 16:01

Traditional tonal music plays with expectations.

Music can do many surprising and unexpected things, but very often music will do what is "expected" meaning that it follows certain conventions.

Let's switch to a language metaphor just for a moment.

If I say "hello, what is your... ", what word do you expect might be next? Do you think "name?" Certainly you would not expect "rhinoceros", you wouldn't expect "hello" to be repeated. Words like those would be unexpected.

In a similar way music has it's own grammar and syntax, and that grammar and syntax creates expectations for a listener.

So, if I play a `V7` chord, it sets up an expectation for a `I` chord. I may or may not play that `I` chord, but an expectation is created. You expect to next hear notes from that `I` chord... and there is a very good chance you will hear them.

Other kinds of expectation can be created. If a melody goes up, eventually it will probably go down. Step-wise movement often continues in one direction. If a melody goes up as DO, RE... there is a reasonable chance that MI will follow. Call and response and other repetition devices also play with musical expectations.

• On the expected/unexpected part: doing what's expected for the majority of the time will make the unexpected part stick out in a pleasing way. Sticking with unexpected for the majority of the time will make the whole thing stick out in an unpleasing way (generally, not always) – Aethenosity Mar 21 '19 at 23:15
• @Aethenosity: And if everything is unexpected, then you call it "atonal" and complain when regular people don't like it. – Kevin Mar 22 '19 at 6:43
• You can create some fantastic melody hooks by playing with the expectations. You expect a certain note, but you replace it with no note at all, or some unexpected note/modulation. – Juha Untinen Mar 22 '19 at 7:57
• "'The volcano is eru___' The volcano is erudite?" -xkcd – user45266 Mar 22 '19 at 15:20
• @user45266 - "The volcano is Eru Iluvatar" - J.R.R. Tolkien – Bob Jarvis - Reinstate Monica Mar 22 '19 at 21:58

You can’t predict only the next tone. Very often you can even tell or guess a whole phrase.

Melodies are built of motifs. These are elements that can be repeated, sequenced or brought back in an inverted form. Music theory and the theory of melody-building that describes the structural principles of melodies call it “question and answer” or “response”, “motif and development”:

If you have checked the motif

do so do sodosodomiso

you can construct e.g. 2 answers:

fa re fa re faretire so

or:

re la re la relarefa la

This can be explained by the inherent logic of a tune and by principles of the melodic shape (“gestalt”) that are saying e.g.:

The whole is more than the sum of its parts.

• I would like to add to this answer that there have been grammar-like formalizations of music as for example GTTM (cf. en.wikipedia.org/wiki/Generative_theory_of_tonal_music) helping to identify and understand such proceseses better. Research relevant to this interface between psychology / perception of music and composition continues to today. E.g. à l'ÉPFL's musicology group around Prof. Rohrmeier (dcml.epfl.ch). – Buttonwood Mar 21 '19 at 22:10
• Thank you for the link! – Albrecht Hügli Mar 21 '19 at 22:19
• Ok, this is like the fourth time I've seen "motive." I assume that's a modernized version of "motif," right? – Aethenosity Mar 21 '19 at 23:16
• @Aethenosity - I think it is just a language difference. In English it is motif. – Doktor Mayhem Mar 22 '19 at 13:01
• I can edit it. I have to learn that the ending -iv changes to -if in English - except if we talk about “ leitmotiv”. ;). umich.edu/~umfandsf/symbolismproject/symbolism.html/… – Albrecht Hügli Mar 22 '19 at 17:35

Because Common Practice harmony is all about dominants resolving to tonics. About setting up tensions then resolving them. Here's a simplistic example:

You know where that penultimate chord wants to go. Often, you'll be satisfied!

• Is this part of a bigger piece? Do you have a link to a recording of this? I'd love to hear it! – drewdles Mar 21 '19 at 22:15
• @drewdles - It's a version of the stock musical phrase "Shave and a Haircut, Two Bits". – Dekkadeci Mar 22 '19 at 0:19
• @Dekkadeci: ...with a rather extended penultimate note. For comedic effect? – supercat Mar 22 '19 at 15:11
• No. Just to emphasize the anticipation. – Laurence Payne Mar 22 '19 at 16:01
• The tune is so familiar that it's hard to judge what the expectation would be when hearing it for the first time. But I'm wondering how much the crotchet rest contributes to creating that expectation? – Michael Kay Mar 24 '19 at 20:38

Your question actually hints at what the "theory" in music theory is about. Following various combinations of notes, some continuations will sound smooth, some jarring, some relaxed, some tense, etc. Many people, yourself included, have an innate sense of what kind of continuation would best fit the nature of the music that precedes it, and much of the purpose of music theory centers around identifying what expectations will be created by various patterns in the music and, conversely, identifying what patterns in the music can be used to create various expectations.

Or, to put things another way, you probably have a sense of how the piece of music would go because the composer didn't want it to be particularly jarring, and music theory predicted that listeners who heard the heard the piece of music up to a certain point would find it least jarring if it continued in the way that many listeners, yourself included, would expect.

Satisfying music (like other art forms) dances on the border between order and chaos.

Music that's totally predictable and repetitive is boring to most of us; but so is music that's totally unpredictable and random.  The most enjoyable music tends to be that which combines the two: that has enough repetition and predictability to bring familiarity and structure, but enough unpredictability to add interest and surprise.  That's where complexity and richness lies.

Obviously, your ability to predict the next note, sound, chord, motif, harmony, or whatever will depend upon your familiarity with the genre, style, composer, &c.  So this is subjective.  (But that should be no surprise.)

So yes, if a melody is in a style/genre you know, then you'll have a non-zero chance of predicting the next note.  But if the music's any good, you won't always get it right!

• Thanks for your great answer. And I appreciate your point about people being able to predict music better when they are used to the genre/artist’s style. What I am more fascinated and interested in, is the ability to make small predictions for pieces that are completely new. Before i posted this question, I played a piece called ‘Low Mist var 1 day 1’ by Ludovico Einaudi, when I realized I anticipated the fourth note correctly. I am aware of Einaudi, but don’t listen to his music, and also realized that it happens occassionally for other music too, hence why I was interested to ask 😁 – drewdles Mar 22 '19 at 17:03

I'm in complete agreement with @gidds answer. For a deep dive into the why and how of our ability to predict the next notes, check out Sweet Anticipation by David Huron. Drawing on both neuroscience and musicology, he makes a compelling case that our pleasure in music derives both from the psychological reward of getting it right and the the thrill of surprise when we don't.