Music expresses that which cannot be said and on which it is impossible to be silent.

The line frames music as a paradoxical language: it communicates what ordinary speech cannot articulate, yet it also compels expression rather than silence. Hugo’s formulation captures a Romantic-era belief that art reaches beyond rational discourse into the realm of feeling, intuition, and the ineffable—grief, longing, awe, spiritual experience. The second clause (“impossible to be silent”) suggests an inner pressure to voice such experiences; when words fail, music becomes the necessary outlet. Read this way, the quote elevates music from ornament to necessity: a medium that both reveals and relieves what is otherwise inexpressible.