Years ago an orchestra colleague was commenting on Maurice Andre's amazing clarity. I'll never forget his six-word summary: "He has contact with every note!"
What does every note require? A clean start, centered pitch, and a good sound. Great players take excellent care of their notes.
There's a quick fix for sloppy articulation, poor accuracy, and faulty intonation. Simply slow down and get a grip on each note. A more relaxed pace gives the brain and the ears a chance to focus on vital details. Only after you can hear an individual note, can you begin the polishing process. Think slow-motion cleansing.
Imagine that every pure note you play rewards you with a crisp ten dollar bill. How much money would you accumulate by the end of the day, if any? Or, if you could cut and paste any of your random notes, would they sound good enough to splice into the Pictures Promenade?
Consider your driving. You shouldn't speed frantically through neighborhoods, blowing past stop signs, riding on sidewalks, and recklessly doing wheelies on private property! No, you carefully obey all traffic signs keeping control of the car at all times. Play as well as you drive. Handle all notes with care. Quality-control matters.
