a piano and guitar piece using the royal road chord progress

K: Cmaj T: 80 TS: 4/4 INST: Piano, AcousticGuitar (nylon/steel, fingerstyle), ElectricGuitar (clean/ambient for middle), UprightBass (or ElectricBass), LightPercussion (brushes/shaker), StringPad (subtle) Mood: Mellow, intimate and warm at the start; gradually uplifting and more energetic/bright in the middle Structure: Verse–Chorus–Bridge (Intro → Verse (chill) → Chorus (lifts) → Verse → Chorus → Bridge (exciting middle) → Chorus → Outro) Summary: The piece is a piano-and-guitar centered pop/acoustic arrangement built around the "royal road" progression (I–V–vi–IV — e.g., C–G–Am–F in C major). Start sparse and chill: gentle piano arpeggios and fingerpicked acoustic guitar, minimal bass and no or very light percussion. Use soft, warm voicings and room reverb to emphasize intimacy. Around the chorus and especially the bridge (the "middle" you want exciting), introduce electric guitar pads or a melodic clean lead, fuller piano voicings, steady light drums (brushes or soft kick/snare + shaker), and bass to drive energy; increase dynamics and rhythmic intensity while keeping the harmonic progression familiar. Return to the mellow texture for the outro to close. This keeps the vibe cohesive while providing a clear, emotional build in the middle.

Model: gpt-5-mini