Use a more appropriate default value when no playing frequency is found.
Return to use of CentDeviationEvaluator.  RangeEvaluator increases execution time far too much.
Change findBracket to search for playing ranges over a much broader range,
and search in both directions if a good solution isn't found the first time.
Optimization can take somewhat longer, but is more robust, particularly
when starting point is too small.
Adjust expected values to conform to actual behaviour of system under test.