“Romance (Andante)” is the second movement of Mozart’s Piano Concerto No. 20 in D minor, K. 466. This movement is often celebrated for its lyrical and serene character. Let’s break down the chord progressions and key changes in this piece.
Key of the Movement:
- The Romance (Andante) is primarily in the key of B-flat major. The notes in the key of B♭ Major are:
B♭ C D E♭ F G A These notes follow the same pattern of whole and half steps as other major scales:
Whole, Whole, Half, Whole, Whole, Whole, Half.
The notes in the key of G minor (natural minor scale) are:
G A B♭ C D E♭ F The G minor scale follows the pattern of whole and half steps:
Whole, Half, Whole, Whole, Half, Whole, Whole.
Chord Progressions:
- Main Theme (B-flat major):major, with a simple and elegant chord progression that can be outlined as follows:
- I (B-flat major) → IV (E-flat major) → I (B-flat major) → V (F major) → I (B-flat major)
- I (B-flat major) → vi (G minor) → ii (C minor) → V (F major) → I (B-flat major)
- Middle Section (G minor):
- The middle section modulates to the relative minor, G minor. This section contrasts with the opening, giving a more somber tone.
- The chord progression here often revolves around the tonic and dominant of G minor, such as:
- i (G minor) → iv (C minor) → V (D major) → i (G minor)
- i (G minor) → iv (C minor) → V (D major) → VI (E-flat major) → VII (F major) → i (G minor)
- Return to B-flat Major:
- After the middle section in G minor, the music transitions back to the original key of B-flat major, reprising the main theme.
- The chord progression is similar to the opening, restoring the tranquil mood:
- I (B-flat major) → IV (E-flat major) → I (B-flat major) → V (F major) → I (B-flat major)
Key Changes:
- Primary Key: B-flat major
- Middle Section: Modulation to G minor (relative minor of B-flat major)
- Return: Back to B-flat major
Summary:
The piece starts and ends in B-flat major, with a contrasting middle section in G minor. The chord progressions are typical of the Classical era, focusing on tonic, dominant, and subdominant relationships, which help to create the beautiful, balanced structure for which Mozart is known. The key changes are relatively straightforward, with the movement primarily oscillating between B-flat major and G minor.
In Mozart’s Romance (Andante) from the Piano Concerto No. 20 in D minor, K. 466, the key changes (modulations) occur on specific chords that act as pivot points, facilitating the transition from one key to another. Here’s a breakdown of where these key changes occur:
1. Modulation from B-flat Major to G Minor:
- Pivot Chord: The modulation to G minor, the relative minor of B-flat major, usually happens smoothly because B-flat major and G minor share the same key signature (two flats). The pivot chord that facilitates this transition is often a D major chord (V of G minor).
- Progression Example:
- B-flat major: I (B-flat major) → vi (G minor) → ii (C minor) → V/V (D major) → G minor
- The D major chord (V) in G minor serves as a dominant that resolves to the tonic (G minor), effectively modulating to the new key.
2. Return from G Minor to B-flat Major:
- Pivot Chord: The return modulation to B-flat major is typically achieved by moving through a G minor chord (i in G minor, vi in B-flat major) and then transitioning to a dominant chord of B-flat major (usually F major).
- Progression Example:
- G minor: i (G minor) → iv (C minor) → V (D major) → VI (E-flat major) → VII (F major) → B-flat major
- The VII (F major) chord in G minor serves as the dominant of B-flat major, smoothly leading back to the tonic (B-flat major).
Summary:
- From B-flat Major to G Minor: The key change occurs on a D major chord (V of G minor), which is a strong dominant that leads into G minor.
- From G Minor to B-flat Major: The return modulation uses the F major chord (VII in G minor, V in B-flat major) as the pivot, resolving back to B-flat major.
These pivot chords are common tools in Classical music to facilitate smooth and logical modulations between related keys.