Music Theory - Playing by ear

Music Theory


 

"Playing by ear"

When we are not studying music using the standard musical notation, we are more likely to hear a piece of music before we come across the musical notation for it. For people like me who are not fluent in using the scientific notation for music, it is easier to like a piece of music (and thus want to play it) after hearing the piece rather than after going through the notation for it.

But to play a musical piece on any instrument just by hearing it involves understanding which notes (and chords) to play and when. The process of getting this information by hearing a piece and thereafter playing the piece can be called "playing by ear".

"Playing by ear" is not something that can be learnt in one shot. It has to progress through different stages, and each stage requires an enormous amount of practice. In the following sections, I will go through these stages one by one. At each stage, I will mention the important things to be kept in mnid while practising.

Finding notes by hearing them

The crudest form of "playing by ear" is, as those who have tried it out will know, to do the following:
  • Play back the original song using a cassette or CD player.
  • After each note occurs, pause the player.
  • Try out a random note on the musical instrument you are using and see if the sound of the note matches the original. Keep trying out different notes till you find one that matches the original.
  • Repeat the same for each significant note in the piece.
    • As you practise this "hit-and-miss" method for more and more musical pieces, the number of "hits" will increase and the number of "misses" will decrease. Unfortunately, this is one stage where we cannot apply any theory, except, of course, that higher notes sound shriller and lower notes sound deeper. Your ear just has to get accustomed to how a note sounds relative to another, so that once the starting note of the piece is found (a bit of hit-and-miss is allowed here, even after lots of practice), the ear should immediately recognize the notes following it.

    Though rhythm and timing is not covered in these pages, it is important to note that for efficient reproduction of a piece of music, you not only have to find the notes occurring in the piece, but also how long each note lasts.
     

    Findng scales by hearing them

    Once you are comfortable with locating a note after hearing it, you can try to find out which scale it is in.  Note that for achieving this, you have to be comfortable with the theory mentioned in my earlier chapter on scales.

    The key concept is that if the notes occurring in a piece of music are part of a given scale, that piece can be said to be in that scale. Keep in mind that the melody might have variations like the following:

    • A melody might change scales in between. a portion of the melody might have notes in different scale than what the melody started out with. To take care of this, I'll introduce the concept of a current scale, meaning the scale of the portion of the melody that we are currently considering.
    • The may be accidental notes. These are notes that are not part of the current scale, but occur here and there in the melody.


    As a simple example (with no scale changes or accidental notes), consider a tune that goes like (only the notes are given, not their durations):

    D E F# E D G B A B C# C# C# D E D.

    No, that is not a tune I know.  I just made that up for the purpose of explanation. Now let us consider whether notes fit into the scales we know - taking a wild guess at scales :

    C Major - F# and C# are not part of C Major, hence it is ruled out.
    G Major - C# is not part of G Major, so that is ruled out too.
    D Major - As you can see, all the above notes are part of D Major. So we can consider the above tune to be in the scale of D Major.

    Well, that's the general strategy for any tune. Keep on eliminating till you get a scale that fits. Sometimes you might get more than one scale that fits. In that case, decide on one of them, and if proves wrong later in the melody, try the other options. If none of them fit perfectly, don't worry - there may accidental notes or scale changes that are causing the confusion - so try "suspecting" some notes as accidental notes and see if everything else fits in one scale, or try considering shorter pieces of the melody to see if there are scale changes. With practice, you should be able to make reasonable decisions at such junctures.

    Exercise

    Find the scale of the following piece (spanning over two lines below):

    A A B C# B A D E F# E
    G# G# A B A G# B E D C#

    Relative minors and majors

    Note the interesting fact that the above notes are also part of the scale B natural minor, which, coincidentally (well, it's more than coincidence), is the relative minor of D Major. One way to decide whether a song is in a major scale or its relative minor is to see frequency of occurrence of the root notes. For example the note D (root note of D Major) occurs more frequently (and at the start of the song too !) than the note B (the root note of B Minor). If this doesn't help the decision, try giving more importance to the notes falling "on the beat" in the rhythm of the music. Sometimes the decision is shifted towards the minor scale, if any of the notes from the melodic or harmonic minor scale occurs in the songs.

    Accidental notes

    Another thing to note is that not all pieces of music will be as "simple" as the tune given above. You might find that most of the notes in the piece fall under a given scale, but some notes, which occur in between, are "out of place", or are not part of that scale. In this case, simply consider the piece to be in that scale (in which most of the notes fall), and mark the "out of place" notes as accidental notes. Accidental notes are put in by the composer to add variety or "spice" to the piece of music.

    Again, this is another step in learning to play by ear, which should receive a great deal of practice. Once you become familiar with the theory, and with finding out the scale of a given piece of music, the music will start "making sense". For example, in a song in the scale of A Major, you will come to expect the notes A, E, D, C#, G#, and so on, to occur. In the same scale, if you find that a note C has occurred, you should realize that it is an accidental note, and you should be able to say where the note "C" stands in relation to the scale of A Major (it stands between the second (B) and third (C#) notes of the scale).

    Finding and guessing chords

    Now that you are familiar with the concept of finding the scale of a piece, it's time to move on and try to find the chords which would sound good if played along with a piece.

    Finding the chords for a given melody can refer to two things:
     

  • Finding the chord that was originally played in the piece.
  • Finding chords that would fit the melody (sound good along with the melody) without knowing the original composition (without knowing the original chords selected by the composer).
    • Finding the "original" chords (the first method mentioned above) is rather a brute-force method, where you listen carefully to the original piece, pick out all notes that are played together and see which chords they form. This is much, much more difficult than merely picking out notes of a melody (single notes) by listening to it. With practice (maybe using the second method described below), you can learn to recognize the "sound" of a chord, relative to a particular scale.

    Now, the process can be made easier if you know what chords to expect for the given melody. "Expecting" chords for a given melody is achieved by the second method.

    Now let us look at the second method in detail. Note that the steps and rules mentioned below may not hold in all cases, but are just guidelines that help you to expect certain chords more than others.

    Suppose you are given a melody to find the chords for. The whole process can be described very briefly in the following steps:

    • Find the scale of the melody using the concepts mentioned previously.
    • Make a list of chords for that scale. That is, list out the chords whose notes are part of the scale you just found.
    • For any note in the scale, you can say that a given chord (in the list you just created), fits the note, if that chord contains the note.
    • Often you'll want to find a single chord for several notes that occur one after the other in the melody. Obviously, it's usually impossible to find a chord that fits each of these notes. So we make a compromise, and try to find the "best fit". To find a chord for a period of time (for a bar, for two beats, etc), find a listed chord that fits the most number of notes in that period. There are a few timing-related issues to be considered here (again, these are not rigid rules, but they can help you in your decisions):
      • Give more importance to notes that sustain for a long time. For example, a note that lasts for three beats should influence the choice of chord more than a note that lasts for just one beat.
      • Give more importance to notes that fall on the beat. For example, in a four beat rhythm, the note that falls on the first beat could be considered "most important", then the note falling on the third beat, then the ones on the second and fourth beat.
    That sums up the method. Doesn't look that long, does it? In the perfect world, where there are no ambiguities like accidental notes or scale changes, this will work fairly well.

    In fact, even in our real world, the above method should give you a clear picture of what chords are most likely to occur in the song. If you come across an accidental note, try a chord that fits that note, and the rest of whose notes are in the current scale. If a scale change occurs, make a new list of "likely" chords for the new scale, and continue.

    Well, that's quite a bit of theory described in a few words. As you probably guessed, it's not complete and it's not perfect.My objective here has been to increase your chances of trying out the correct chord (that was used originally in the melody) early in your "improved" trial-and-error process, not to guarantee a "hit" the first time. Like in any art form, there are no unbreakable rules in music either. In fact, breaking the rules could help create better music.

    An Example

    With that said, let's try out the method described above, with a real example - the first two lines of "Edelweiss" from "The Sound Of Music". Each note (or "-", used to indicate that the previous note still sustains itself) lasts for one beat. I'll use "/" to separate bars (used to indicate a fixed amount of time). A subscript indicates a lower octave, and a superscript indicates a higher octave. For example D1 indicates D of the higher octave. An octave starts at C and ends at B.

    Edelweiss

    E - G / D1 - - / C1 - G / F - - /
    E - E / E F G / A - - / G - -
    E - G / D1 - - / C1 - G / F - - /
    E - G / G A B / C1 - - / C1 - - /

    A quick examination of the different notes that occur in the above piece indicate that it is in the scale of C Major - which it indeed is. But a more thorough examination will reveal that all of the notes are also in the natural scale of A minor. We're at our first decision. Unfortunately, there is no way to choose between A minor and C Major. Let's first try C Major and then A minor.

    So, let us create a list of chords that fit into the scale of C Major:

    C Major (C,E,G)
    F Major (F,A,C)
    G Major (G,B,D)
    G seventh (G,B,D,F)
    A minor (A,C,E)
    D minor (D,F,A)
    E minor (E,G,B)
    ...and lots more.

    Let's take the first bar "E-G". Note that C Major fits it well (it contains E and G), but then, so does E minor, and, for that matter, so does C Major seventh ! We're faced with our second decision, the first in the choice of chords. One rule that can apply here is - the simplest choice is probably the best. We are assuming (remember, we're not sure about the scale yet) that the song is in the scale of C Major, and the chord C Major fits the bar perfectly - so why not go for it ? It turns out that it's the correct choice.

    How do we test if we made the right choice ? Simply play back the original song/melody, and play the chord which we decided (C Major) (using any musical instrument), and see if the chord sounds like that in the melody. This is a difficult step to master. You have to practice to concentrate on listening to the harmony created in the original piece, and comparing it with the harmony created by the chord you are playing.

    You can make similar decisions about the remaining chords in the piece. You'll find that the chords you decide based on a scale of C Major, fit better than if you had based the piece on the scale of A minor. Unfortunately, this is another "trial-and-error" part of the method.

    Now let's short-circuit our discussion, and go to the last seventh and eighth bars of the piece:
    A - - / G - -

    Following the steps I described, let's say we decided on F Major and C Major for the two bars respectively (assume that we chose F Major over A minor and D minor because we were considering a major scale). If you try comparing these chords (by playing them) with the ones you hear from the music, you'll find that they don't match. Taking the scale to be A minor won't help either.

    It turns out that the actual music uses D Major instead of F Major, and G seventh instead of C Major - weird, ain't it ? But when you listen to the music, you'll know that these chords blend in perfectly. Indeed, D Major contains A, and G seventh obviously contains G, but why does it sound really good ? What just occurred (in that portion of the piece) was a temporary change of scale to G Major, and then a return to C Major. Note that the chord D Major fits into the scale of G Major. Perceptually (for the listener), what happens is that the chord D Major, besides fitting the note A, "leads" the listener to the scale of G Major (which is closely related to C Major - with just one note different, an F# instead of an F, and the chord D Major contains F# !!!), so by the time the bar containing D Major is over, the listener is almost expecting to hear something in the scale of G Major. So why did the composer choose the chord G seventh instead of G Major ? He wanted to return to the scale of C Major, and the chord G seventh, besides being a smooth transition from D Major, leads the listener to expect something in the scale of C Major to come next !

    I know that I have used some arguments above which may be quite subjective, and without properly explaining all the concepts behind them. I only wanted to make a point that variations occur due to many reasons - in fact, the variation we saw above is quite a common technique - and the only way, in my opinion, to get used to them is through practice and experience. With practice, you should come to recognize such variations simply by hearing them.
     

    Conclusion

    I hope these pages have given you enough insight into the theory of music, to systematically explore and understand a piece of music. Music has always been an art form rather than a science, so I don't feel that any number of rigid rules can fully explain the beauty of it. But trying to understand as much of it as you can, will help you to appreciate its intricacies and to realize the sheer depth of it still to be understood.