Who doesn't love a good bass line? They're instrumental to driving the groove in modern styles like funk, jazz, rock, and more, but they've actually been an important tool in a composer's arsenal for centuries.
For example, many pieces written in the Baroque period, which ranged from 1600 to 1750, used bass lines to give a solid foundation to their highly ornamented melodies. Composers of the time often built entire pieces on a repeating bass line called a ground bass or ostinato, over which the melody would develop.
One of the most elegant ways they did it was through the passacaglia, a form that originated as a dance in early 17th-century Spain and spread to Italy. It's defined by a brief sequence of chords outlining a cadential formula.
"The passacaglia was redefined in late 1620s by Italian composer Girolamo Frescobaldi, who transformed it into a series of continuous variations over a bass (which itself may be varied)," Classic Cat explains. "Later composers adopted this model, and by the nineteenth century the word came to mean a series of variations over an ostinato pattern, usually of a serious character."
One perfect example of the form's evolution is found in George Friedrich Handel's Harpsichord Suite in G Minor (HWV 432) from 1720. The final movement, simply named "Passacaglia," was reworked by Norwegian composer, conductor, and violinist Johan Halvorsen in 1894.
Halvorsen took the main theme and arranged it for violin and viola, expanding the material to include more virtuosic passages.
"A total of 12 variations comprise the work, and, though Handel’s original contained 15, Halvorsen extended the Baroque work in total length, breadth, and flair, drawing heavily upon his own prodigious expertise as a violinist," the Colburn Conservatory of Music writes. "The piece is technically challenging for both performers, showing off a wide range of techniques, tempos, colors, and atmospheres."
You can witness how the piece unfolds from a simple statement to a flurry of notes in this performance by Itzhak Perlman and Pinchas Zukerman:
More recently, the piece inspired a piano arrangement that has become popular with budding pianists. Played by Yannick Lowack, this version takes the theme from measures 37 to 40 of the Halvorsen arrangement and expands on it through variations. The melody explores a similar theme throughout, but the ostinato bass line brings it all back to the Baroque.
Lowack arpeggiates the chord in the left hand. The song is transposed to A minor and features a circle progression, a cycle of chords based on the circle of fifths. In this instance, the chord progression is Amin-Dmin-G-C-F-Dm-E-Amin. The bass line applies the same formula to each chord, starting with a low root note and jumping an octave to play the root, fifth, third, and octave again.
Compared to the violin/viola arrangement, which is sometimes referred to as the "Impossible Duet" thanks to its relentless double stops and extreme demands on both players, the piano arrangement takes a much calmer, introspective approach.
Whether you're looking for a complex thrill or a meditation on a theme, "Passacaglia" delivers with a steady, grounding bass line.