What is a common characteristic of the Alberti bass style?

The Alberti bass style is defined by its distinct use of a broken chord pattern, typically played in the left hand, which supports the melody in the right hand. This pattern consists of the notes of a chord played in succession, often following a specific sequence such as the root, the fifth, and the third of the chord, creating a flowing, arpeggiated texture. This accompaniment style provides a harmonic foundation while allowing the melody to stand out, which is characteristic of many Classical period compositions.

While other options touch on important musical elements, they do not specifically describe the essential quality of the Alberti bass. Complex polyphonic melodies tend to involve multiple independent melodies rather than the straightforward, supportive role of Alberti bass. The combination of varying tempos is also not a defining trait of Alberti bass, and a focus solely on rhythm neglects its harmonically rich role within a composition. Thus, the unique aspect of the broken chord pattern is what solidifies the reason for B being the correct answer.