Ah, the language of the piano for a sad song! While there's no single "sad song scale," certain keys and chord progressions tend to evoke feelings of melancholy, longing, and introspection. Here are some common approaches and keys often associated with sad music, keeping in mind the Billie Eilish "What Was I Made For?" vibe often utilizes a more contemporary and sometimes less traditionally "sad" harmonic language but still carries emotional weight The minor third interval (e.g., A to C in A minor) is a key characteristic that gives minor chords their sad sound. Using Suspended Chords (sus4 and sus2): These chords create a feeling of unresolved tension that can add to the sadness. For example, an Asus4 chord resolving to Am. Adding Seventh Chords (minor 7th, diminished 7th): These chords add complexity and often a more emotional depth. For example, an Am7 or a Bdim7.   Pedal Points: Sustaining a bass note (often the root of the key) while the chords change above it can create a sense of unease or contemplation. Simplicity: Her songs often feature relatively simple chord progressions, but the emotional impact comes from the melody, vocal delivery, and atmospheric production. Chromaticism: She sometimes uses notes and chords outside the main key (chromaticism) to create unexpected and emotionally charged moments. Open Voicings: Chords played with wider intervals can create a spacious and sometimes vulnerable sound. Focus on Bass: The bass line often plays a significant role in establishing the mood. Ah, the language of the piano for a sad song! While there's no single "sad song scale," certain keys and chord progressions tend to evoke feelings of melancholy, longing, and introspection. Here are some common approaches and keys often associated with sad music, keeping in mind the Billie Eilish "What Was I Made For?" vibe often utilizes a more contemporary and sometimes less traditionally "sad" harmonic language but still carries emotional weight: Keys Often Associated with Sadness (Traditionally): Minor Keys in General: Minor keys inherently have a darker, more somber quality compared to major keys. A Minor: A very common key for sad songs. It has a natural, resonant feel on the piano. E Minor: Another frequently used minor key, often feeling introspective and melancholic.   D Minor: Can evoke a sense of yearning or a gentle sadness. C Minor: Often feels quite dramatic and intensely emotional. F Minor: Can have a particularly heavy and somber quality. B Minor: Sometimes feels more restless or uneasy. Why Minor Keys Work: The minor third interval (e.g., A to C in A minor) is a key characteristic that gives minor chords their sad sound.   Chord Progressions Common in Sad Songs: i - iv - v (in minor): For example, in A minor: Am - Dm - Em. This is a fundamental minor progression that can sound very poignant. i - VI - III - VII (in minor): For example, in A minor: Am - F - C - G. This progression has a more cyclical and often melancholic feel. i - VII - VI (in minor): For example, in A minor: Am - G - F. This can create a sense of longing or unresolved tension. Using Suspended Chords (sus4 and sus2): These chords create a feeling of unresolved tension that can add to the sadness. For example, an Asus4 chord resolving to Am. Adding Seventh Chords (minor 7th, diminished 7th): These chords add complexity and often a more emotional depth. For example, an Am7 or a Bdim7.   Pedal Points: Sustaining a bass note (often the root of the key) while the chords change above it can create a sense of unease or contemplation. Billie Eilish Style Considerations: Simplicity: Her songs often feature relatively simple chord progressions, but the emotional impact comes from the melody, vocal delivery, and atmospheric production. Chromaticism: She sometimes uses notes and chords outside the main key (chromaticism) to create unexpected and emotionally charged moments. Open Voicings: Chords played with wider intervals can create a spacious and sometimes vulnerable sound. Focus on Bass: The bass line often plays a significant role in establishing the mood. In the context of our breakup song: Considering the themes of being left hanging and silent crying, a key like A minor or E minor could be a good starting point. We could use a relatively simple progression like Am - G - C - F (i - VII - III - VI in A minor) or Em - D - C - G (i - VII - VI - III in E minor), focusing on the emotional delivery and perhaps adding suspended chords or minor 7ths for extra color.