After 75 years as a cello teacher, Ariel Witbeck prepares to cut back a bit small cellos, for instance), of varying quality. “One was left on my doorstep, literally in pieces,” Witbeck recalled. That delivery, and the fact several of her earliest acquisitions (all small WITBECK: She’s working to end cello rental-sales business – not ‘teaching’ cellos) were initially stored