The Passacaglia with its dual attribution to Handel and Halvorsen is a famous virtuoso piece for violin and cello (or violin and viola) published by Norwegian composer Johan Halvorsen in 1894 and based on the finale movement from the harpsichord suite in G minor (HWV 432) published by German composer Georg Frideric Handel 1720. Handel composed numerous harpsichord suites comprising dance movements, sometimes concluding with the traditional Baroque passacaglia, a term originally designating a Spanish "street dance" though the earliest extant examples are Italian. The essential feature of the passacaglia is short, resolved chord progression repeated over and over as a continuous harmonic bedrock for a series of improvisations or inventive variations. Numerous Baroque composers wrote such variation movements for harpsichord, organ, violin or ensemble using the nearly interchangeable terms passacaglia or chaconne with several celebrated examples from French and German composers especially J. S. Bach. Halvorsen was a celebrated violinist, conductor and composer who is remembered today primarily for his brilliant "extrapolation" of Handel's passacaglia for daring ensemble of two stringed instruments. The "theme" is a brief four-measure sequence of eight chords with a characteristic dotted rhythm generating a series of thrilling variations in a tour de force of musical invention. The spare resources of violin and cello require numerous double and triple stops, multi-note chords on each instrument to create a full four-part harmony. Some of the variations take an alternative approach using swift melody lines that create a linear harmonic effect over time. The result is scintillating dialog for two master players frequently expanding to four and five simultaneous parts. - Kai Christiansen on earsense.org