Daniel Barenboim: Inner Ear

No matter what instrument you play, or whether you conduct or sing, you will only produce the sound you want if you can hear it in your head a fraction of a second beforehand. This is the part of music which is impossible to teach. I could teach people how to put down their hands, how to balance the two Ds, the three Gs and the three Bs in the opening chord of Beethoven's G major concerto, that there is a register where the note has a tendency to be louder, and that the thumb has more weight than the little finger. But if a student is unable to imagine the sound before he starts to play - even if it differs from what I am trying to explain to him - he wil never produce the sound he wants. This ability to hear the sound and the phrasing you want in the inner ear is one of the most essential qualities.