The hardest thing is to count the number of bars of silence

The hardest thing is to remain focussed

The hardest thing is to attack a note neatly

The hardest thing is to keep up the tempo

The hardest thing is to play in tune

The hardest thing is to maintain a good quality of timbre

The hardest thing is to respect the articulations

The hardest thing is to maintain a certain consistency

The hardest thing is to lend variety to the expression

The hardest thing is to add nothing

The hardest thing is to obtain the desired nuance

The hardest thing is not to arouse boredom

The hardest thing is to surprise the audience, and oneself in the process

But not too much

The hardest thing is to emit no sound at all during the rests

The hardest thing is to per-form

The hardest thing is to produce a certain hue

The hardest thing is to set up a certain atmosphere

The hardest thing is to observe a certain logic

The hardest thing is to be faithful to the score

The hardest thing is to overcome all the difficulties

Rightly

The hardest thing is to unfold a hidden meaning, but without being too noticeably explicit

The hardest thing is to bring difference into unity

The hardest thing is to merge into the whole

The hardest thing is to appear indispensable

And vice versa

The hardest thing is to conclude