Stanley Turrentine was one of the great jazz talents of our day. His music was swinging, intense, dynamic and volatile, and more importantly his tone was ever personal. The story I was told second hand was that his father had him practice only one note at as time until it was absolutely perfected tonally. This was done facing a corner in the house in order to hear subtle timbre nuances.
Stanley Turrentine "Impressions" (YouTube, 1970)