Craft a somber acoustic guitar piece in the style of a Spanish funeral march (70 BPM). Layer a simple, repeating chord progression with a plaintive upper melody that mimics a vocal lament. Prioritize dynamics—soft whispers contrasting with resonant strums—and avoid any percussive elements to maintain stark emotional purity." Key elements: Tempo (70 BPM), structure (repeating chords + vocal-like melody), dynamics (soft vs. resonant)