Playing by ear is the ability to play a piece of music (or, eventually, learn an instrument) by simply listening to it repeatedly. The majority of self-taught musicians began their education this way; they picked up their instrument and began playing an easy melody from a well-known song, slowly picking out the notes as they went along. And even after these musicians master their instruments or a particular song, playing by ear still plays a large role. Many pop and rock bands don't play or write their songs based on sheet music, they figure the songs out by playing by ear. It's even common among non-musicians. Ever sit down a piano and mindlessly pick out the tune to "Mary Had a Little Lamb"? What about grabbing a guitar and suddenly finding yourself playing the opening licks to "Smoke on the Water"? That's playing by ear. You're able to play part of the song just because you've heard it so often.

Since music is basically composed of 3 elements – melody, rhythm, and harmony, it is logical that there are also 3 basic steps to learning to play music by ear:

Charting the contour of the melody

Tunes move higher and lower – up and down – as the song progresses. Being aware of that movement is the first step. Once you mentally define the parameters of the melody, you can then begin to hone in on picking it out on your instrument. As an example, think of “Joy To The World”. We’ve all sung it a zillion times, but have you ever noticed that the melody moves down exactly 8 steps (an octave), then gradually moves back up in increments, then repeats the down movement, etc. The entire melody is contained within those 8 notes, so you now know the parameters of the song and can begin to pick out the melody intelligently.

Harmonizing the melody with matching chords

The second element of music is harmony, and you can harmonize any melody just by matching the supporting chords to that melody. For example, if the melody is a “G”, you can harmonize that melody by using a chord with G in it, such as the G chord (G, B, D), the C chord (C, E, G), or the Em chord (E, G, B), or the Eb chord (Eb, G, Bb) and so forth. By using your ear to guide you, you can learn to harmonize the melody of most any song using matching chords.

Using an appropriate rhythm that matches the feel of the song

This is usually the easiest part, since most people “feel” the beat and don’t have to do any mental gymnastics to come up with an appropriate rhythm for a song. But for those of us that might be “rhythmically challenged”, just by knowing that there are basically two meters available – duple meter and triple meter -- that can be combined in infinite combinations, we can give the song either a “3” feeling (likea waltz or a jazz waltz) or a “4” feeling (like swing or a march or a ballad).

Playing by ear is a valuable technique for many musicians; learning songs based solely on hearing them is a great way to understand song and chord structure. In fact, a great number of rock and pop musicians learned to play their instruments this way. Instead of picking up a book or taking lessons, they concentrated on figuring out the notes and rhythms to a song until it was mastered. Then they moved on to another song. And another.

Gradually, they learned their instrument just by playing by ear -- and in the process learned how to effectively structure a song in that particular genre. Playing by ear is also beneficial in helping a musician develop his or her own style; sure, they'll at first mimic the style of the song they're imitating, but the amalgamation of the music that they're playing by ear will help them create something distinctive, something indicative of them only.