The purpose of the present investigation was to analyze 15 performances of
Bach's Suite Number 3 for Violoncello solo, Bourree Number 1 and determine
what patterns of rhythmic variation (rubato) were used by the soloists. Dat
a were collected directly from digital recordings of performances, and rese
archers used computerized analysis methods to determine the onsets of each
beat to the nearest millisecond. Results indicated that the soloists demons
trated four identifiable and similar trends in these performances: (a) perf
ormances of new phrases began a little slower to emphasize the beginning of
the new phrase, followed by an acceleration; (b) each repetition of a sequ
ence was quickened; (c) conclusions of a musical idea were marked by a noti
ceable deceleration several beats in advance of that conclusion; and (d) th
ere were several variations in timing that could be linked to physical chal
lenges inherent in the musical instrument.