What defines Alberti bass?

Alberti bass is characterized by its use of broken chord patterns in the accompaniment. This style typically consists of playing the notes of a chord in a specific order, usually following a pattern like the root, fifth, third, and back to the fifth. This creates a light and flowing texture that is commonly found in Classical period music, providing a harmonic foundation while also maintaining melodic interest.

The effectiveness of Alberti bass lies in its ability to support a melody without overshadowing it, as the broken chords create a rhythmic and harmonic base that complements the main musical line. This contrasts with the other options, which describe different musical techniques or aspects unrelated to the specific structure of Alberti bass. For instance, repeated single notes do not form the alternating rhythmic pattern typical of Alberti bass, layering different melodies suggests a counterpoint technique rather than a harmonic accompaniment style, and strict harmonic progressions focus on adherence to specific chords rather than the fluidity offered by broken chords.