I have many times seen that pianists that can read sheet music and sightread very well feel uncomfortable when they are asked to accompany a singer without the aid of sheet music notation.

Personally I have been asked many times to play piano to singers who wants to sing in another key then the one in the sheet music available. This happens because I have developed my ability to play by ear and to change keys on the go.

Of course, someone could transpose the music to a lower key and write it down in order to play sheet music but it is much work involved and often you will not have time to write the music down.

If you are playing popular music it can actually be an advantage to play by ear to get into the right mood and play more musically.

But all this presupposes that you have the ability to play piano by ear and that you can play various styles of music.

I know of some piano players who can't play a note of sheet music. I guess they have earlier in their life been scared off by sheet music notation or maybe they have seen some pianists playing with accuracy but too mechanically for their taste. Maybe they just think that it is too much hard work involved!

I think that there are some misconceptions pertaining to playing by ear and playing sheet music. Some people think that sightreading pianists have to be bad at playing by ear and that improvising pianists need to be poor sight readers.

Well, the truth is that you will be good at what you practice. If you practice both sightreading and chord playing you will become better and better in these areas.

If you are a classical pianist with the ambition to be able to play by ear you can develop this ability as you practice your repertoire and learn new sheet music. Here are some suggestions:

1. Develop your ability to understand chord theory. This can be done as you practice a piece of sheet music. In classical piano pieces you will find passages with chords that you can investigate and learn a lot from. In the first bars of Fur Elise for example you will find the chords Am and E-major. As you play this piece you will find a lot of common chords intervowen in the music.

To spot chords and scales as you practice a piece of classical music will help you put more intellectual power into the enterprise and will also help you memorize the music better.

2. Learn licks from your piano pieces. When you find passages in the music you play that you like and want to incorporate in your repertoire of licks and phrases to use you can memorize them and play around with them trying to improvise, changing notes here and there and transposing them. Many classical piano pieces are filled with interesting chord progressions and melodic phrases.

3. Playing scales. If you include playing scales in your daily routine practice as a classical pianist you might benefit from also using the material in the scales in developing you sense for melodies, and licks. Play around with the notes, try to create interesting melodies and small licks and using chords as you play. This will help you practice both your finger dexterity and musical abilities.

There are many more things you can do to develope your ear and your sense for chords and improvisation. The important thing is to see possibilities in the classical piano sheet music you play.