  Detrended Fluctuation Analysis (DFA), suitable for the analysis of
nonstationary time series, is used to investigate power law in some of the
Bach's pitches series. Using DFA method, which also is a well-established
method for the detection of long-range correlations, frequency series of Bach's
pitches have been analyzed. In this view we find same Hurts exponents in the
range (0.7-0.8) in his Inventions and sinfonia.
