I'm a beginner on piano who plays be ear using pentatonic scale and I'm having hard time accompanying the melody with a chord with the left hand. I can easily play the melody to any song but if I want to accompany someone singing, I don't know what chords to use.

The way I play chords is for example in key of C if the melody rests on note G, I would play G major chord if it rests on C play c major, so I follow the melody and play matching chords to the note of the melody. The problem I'm facing is that It's hard to determine the key by ear where the melody rests when someone is singing and then playing a matching chord to that key.

Is there an easier way to do this? Writing out the chords to the song would work out but I was wondering if it could be done just by listening

  • I think you should unlearn the strange idea of thinking that only G chord is OK when G note is sounding. Simple arrangment means at least defining the key (e.g. in Cmaj the chord C will be the tonic - chord I), G is chord V, F is chord IV. If you hear that the song is developing from I to IV to V than back to I, you see the structure and choose these chords C-F-G-C. So the choice of chords is more about seeing how the song develops.
    – alexsms
    Dec 18, 2018 at 7:48
  • If you want a magic trick, add a sixth (e.g. in C major, for a C melody note, add an E harmony note below, for D add F) below the melody. Whatever the melody note is, add a sixth below it. MAGIC! It's completely mechanical, you don't even have to know about any chords, just the scale. But don't call yourself a musician then. :) The idea of matching chords is a misconception. For any melody, there's any number of plausible, suitable chords that could be used, and they'll have different feelings and possibilities for voice leading etc. Some chord choices might feel unexpected or unconventional. Dec 18, 2018 at 10:04

4 Answers 4


For finding chords to melodies, there's just one word: practice. There's no other way. There's no substitute for hearing and feeling. Forget about the "this note, so this chord" magic cheat idea. In some cases tricks like that can be applied, but it would still only improve your hit rate from "completely random" to "not completely random" level. Would you be happy if you could recognize your friend's face in a crowd even as much as 60 % of time, using some trick?

Learning the skill consists of two parts: (1) producing i.e. playing, and (2) listening. To play "by ear" means listening to an example and trying to answer the question "what would I play to make it sound like that".

To answer that question successfully immediately after hearing something, you have to have played many things and heard what they sound like many, many times, in many different contexts. When you're not very skilled and experienced yet, you'll have a narrower and less familiar palette of things to try, so there'll be more trial and error. If it doesn't sound like what you wanted, try something else. Keep practicing and you will get better. Your musical palette will expand, and the "hit rate" will improve.

Here are some exercises and hints to try:

Find the melody and chords to simple songs by ear. "London Bridge is Falling Down", "Twinkle, Twinkle, Little Start", "Happy Birthday", "Hit the Road, Jack", etc. First in a familiar key, like C major, and then do the same in other keys.

For finding the key, locate the home base note ("tonal center" or whatever). Some people try to explain what the tonal center feels like, but you have to learn to feel it. You gradually learn what it feels like by playing simple songs in different keys. In the key of C, what does the C note feel like? In the key of C, the home base is C. In the key of F, the home base is F. Learn to know what F feels like, when you're playing a song in F.

To establish a key, play a I - IV - V - I cadence.

  • To establish the key of C major, play the chords: C - F - G - C.
  • To establish the key of F major (key signature: 1 flat), play the chords: F - Bb - C - F.
  • To establish the key of G major (key signature: 1 sharp), play the chords: G - C - D - G.
  • To establish the key of A minor, play the chords: Am - Dm - E - Am.
  • etc.

(That's also a clear way to start a song. First play a I - IV - V - I cadence, and play the song's starting pitch and chord, before the singer starts singing. ;))

To play a simple song in a new key, first establish the key (see above), and then find the melody and accompanying chords by ear. Repeat. At first it is hard, but you'll get better at it. No gain without pain.

To find a melody by ear, you have to have a reference to compare to, so it has to be a song you know well. Play, listen, compare.

To find chords by ear: trial and error, lots of trial and error. Play simple songs that can be played with e.g. I/IV/V i.e. C, F and G major chords in the key of C major. Try each chord and listen. Maybe someone should pick "safe" songs for you to practice with, but in any case, there has to be a lot of "babbling" like what babies do when they start learning to speak. When you're a grown-up, you'd like to skip that embarrassing phase, and jump straight to respected legitimate things, but no can do.

You have to know what a "I chord" feels like, what a "IV chord" fees like, what a "V chord" feels like, etc. Does something feel like a V chord? Does it feel like a I chord? If you don't get any such feelings, then you haven't practiced enough. Practice more.

Like Tim says in his answer, a good bread-and-butter set of chords is, three chords of the major key and three chords of the minor key. For songs in the key of C major / A minor (key signature: no sharps/flats, white keys) they would be, C, F, G, Am, Dm, E (i.e. G sharp in that chord, E-G#-B). Babble with those six chords, and try to accompany melodies you know with them.

To learn to identify and analyze the things you're hearing, alter the components (notes) and listen to what the changes do. Play the notes of chords one at a time, leave out a note, move a note up or down, etc.

To get more ideas about things to try, check out song books (lead sheets) and try to understand the role of each chord. I, IV, V, ii, vi, etc. When you see an accidental in the melody, there's probably a temporary scale change that's also reflected in the chords. For example, in a song that's in A minor key (key signature: white keys), there might be an A major chord before going to a Dm, and the melody must take that into account and play a C# instead of C. Or there might be a Gm and A7 before going to the Dm, both of which have "non-white keys". Tricks like this are common in songs, but trying those chords in that context might not cross your mind by just randomly poking at chords.


Working on a very simple (but effective, and often accurate!) premise that a lot of songs have three main accompanying harmonies, it's not too onerous.

Most songs will start on the key chord; if there's an anacrucis, the first main bar will be on that. Call that the I chord, in whatever key. Usually, we can feel a change coming, and with two other chords to choose from, IV and V, there's a 50:50 chance just by guesswork. But a hint is if it sounds like it's going up from that I chord, rather like a 12 bar song does in bar 5, then IV is a better bet. When the next change is felt, there's still 50:50 - back to I, or onwards to V. That should be an easier one to forecast - back home, or ever onwards.

Be aware that just because there's a G note sung, doesn't automatically mean it's over a G chord - in whatever key, in reality. In a key, there's a very good chance a main note sung also belongs in the harmony. That's fine. G note is obviously in G chord. But it's also in C chord. 50:50 again! But it's not in F (the IV of C), so there's little chance of that harmony being an F chord.

Also be aware that sometimes a chord can and will continue for three or four bars - rarely longer in most songs - so even though the melody may be changing, it doesn't mean the chord has to, or will.

Taking the harmony further, using diatonic chords (those using only the notes from the key), there are also three minor chords which come into play. ii, iii and vi, the minors. Again, after a while using all six, there's a good chance of guessing. If experience tells you it's going to be a minor, there's a 33% chance of hitting the right one.

Private practice with more simplistic tunes - Happy Birthday, Christmas songs, national anthem, etc., will help. A lot of songs can be simplified down to three chords, and won't sound too bad, but you'll hear things like there's one note from a chord that isn't quite right. Have a delve into triads, but also 4 note chords, and also look at the circle of fifths, as sometimes tunes modulate, and use extra chords which are often very next door neighbours looking at that circle.


Study how songs HAVE been harmonised. Sometimes the 'three chord trick' is appropriate, sometimes not. (For a whole load of current popular music, it isn't.). By far the easiest way of doing this is by reading notated music.

  • Looking at ready-made answers is of course easy, and it's an excellent thing to do, if you have no idea what an answer might look like, or if you've tried but failed to produce a satisfactory answer. But IMO it's very important to try and err. :) Dec 18, 2018 at 12:43
  • It's not a matter of cheating by looking up the answer for one particular song. More of being familiar with a wide range of music, getting familiar with how songs in general are harmonised, in various styles.
    – Laurence
    Dec 18, 2018 at 14:08

Don't stare too hard at a tree, look at the whole forest.

When you were a baby, there was no trick, shortcut or method for teaching you to speak. You did your best to imitate the baby noises your parents made until you finally latched onto one and they rewarded you with affection and joy whenever you said it. Eventually you learned that imitation yielded results and putting words together was a science and art. Here you are today, improvising sentences.

Likewise, there are no tricks, shortcuts or methods for learning harmonization. Harmonization is what YOU want it to be. There is no wrong, only what you wish to communicate.

To discover those you need to do five things: Practice, study theory, sing everything, listen to everything, experiment. The same things you did as a baby.

Here is a little experiment for you. With your right hand play a C. Just an octave lower play an Eb chord. Now play the C and in the left play a D chord. Now a Db. Resolve it to the C. Put all four together in a sequence. Try the C with other chords such as an F# (I love b5 chords).

Now you can see that multiple chords can fit over one note. Try this: Play a simple pentatonic melody in your right hand in the key of C. In your left hand, alternate between a C and Bb chord every bar. Don't like it? Try a C and F. C and G?

Try experimenting with modes. This IS a cheat trick method but you should learn the modes properly. Play a C note in your left hand with any rhythmic pattern you like. Now play with a few scales in your right hand. They don't have to be SCALES but notes of that scale. Try the G scale (lydian) with a focus on the F# (flat fifths again). Try a Bb (dorian). One of my favorites is the locrian, Db. I use Locrian as a passing melodic harmonization for either shock, color or I don't know what else to do.

So, there are no cheats, tricks or methods. Only practice, study, experiment and practice some more. Oh, and listening to other people, then steal their ideas.

Everyone steals. I remember as a kid listening to the band BOSTON as they played their song FOREPLAY and I immediately recognized a chord progression from Sinfonia in Bach's Cantata 29. It is at the 1:28 mark of the song.

Whenever I improvise classically I throw in that progression and everyone thinks I'm a genius but I'm really just a thief. As you were reading this, I took your wallet.

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