1derogatory Music that is more impressive in its written form than when heard in performance.
2poetic Something that is pleasing to the eye in a manner likened to listening to music, especially in being visually rhythmic, varied in colour or tone, etc.
Musical notation which employs visual symbols or other graphical features (usually drawing the attention of the reader or performer to elements of the musical or lyrical content) that do not affect the sound of the music when performed.
Frequently with reference to late medieval and Renaissance music.
Early 19th century; earliest use found in The Gentleman's Magazine. From eye + music.