From a Platonistic perspective, ideas are eternal and unchanging, constituting the foundation of reality. An idea itself does not change; it is a principle, immutable in essence. This approach inherently establishes a hierarchy, valuing the world of ideas—understood as objective truth—over the sensory world—seen as deceptive and unstable. Against this backdrop, this paper examines the nature of musical ideas as they emerge from Marcel Proust’s work, exploring their potentially antiplatonistic implications and the philosophical insights they inspired in influential 20th-century thinkers.