Example 2. Op. 19, six recordings of Eduard Steuermann in comparison with average values from 40 recordings by other pianists: duration (above left), main tempo (lower left), percent values (as a percentage of the total duration, above right), and relative standard deviations (expressed as a percent of the main tempo, lower right); the values for the live recordings (1954, 1957b, 1962) are italicized, as are the tempo suggestions from the letter to Michael Gielen, July 24, 1942