While Ludwig van Beethoven's Piano Sonata No. 14, famously known as the "Moonlight Sonata," is not binary in its overall three-movement structure, its individual movements employ different forms. Specifically, the second movement, Allegretto, features sections that are structured in rounded binary form.
Understanding Form in Moonlight Sonata
Beethoven's Moonlight Sonata is a classic example of a multi-movement sonata, typically comprising three distinct movements:
- Adagio sostenuto (First Movement)
- Allegretto (Second Movement)
- Presto agitato (Third Movement)
Each movement contributes to the sonata's overarching narrative but uses different formal designs.
The Second Movement: Allegretto and Rounded Binary Form
The second movement, a relatively brief and lighter interlude between the somber first movement and the turbulent finale, is structured in sections that adhere to a rounded binary form. This form is characterized by two main sections (A and B), where the A section often returns, sometimes slightly varied, at the end of the B section (A-B-A'). This creates a sense of return and balance.
Key characteristics of this movement's form and texture include:
- Rounded Binary Structure: The internal sections of the Allegretto movement exhibit the A-B-A' pattern characteristic of rounded binary form. This provides a clear, balanced structure within the movement.
- Counterpoint as Main Texture: Throughout this movement, counterpoint serves as the primary musical texture. This involves two or more independent melodic lines played simultaneously, creating a rich and intricate sound.
- Unique Key Contrast: Unlike typical scherzos or minuets where there's often a clear contrast between major and minor keys in different sections, the second movement of the Moonlight Sonata predominantly remains in major. The key contrast, if present, is minimal, making it distinct from the traditional expectations of its functional role within the sonata.
Overview of Movement Forms
To further clarify, here's a general overview of the forms often associated with the movements of Moonlight Sonata:
| Movement | Tempo | Common Form/Structure |
|---|---|---|
| First Movement | Adagio sostenuto | Modified Sonata-Allegro Form (without a typical development) |
| Second Movement | Allegretto | Rounded Binary Form (sections) |
| Third Movement | Presto agitato | Sonata-Allegro Form |
What is Rounded Binary Form?
Rounded binary form is a musical structure that evolved from simple binary form. It divides a piece into two main sections, often repeated.
- Section A: Presents the initial musical material, typically moving from the tonic key to a dominant or related key.
- Section B: Explores new melodic or harmonic ideas, often moving through different keys, before returning to the home key.
- Return of A (A'): A significant portion of the opening material from Section A returns, usually in the tonic key, at the end of Section B, thus "rounding off" the form.
This structure allows for contrast and development while ensuring a satisfying return to familiar material.
Conclusion
In summary, while the Moonlight Sonata as a whole is a multi-movement sonata, the sections within its second movement (Allegretto) are indeed in rounded binary form, a characteristic that contributes to its balanced and concise musical design.
