Musically innovative

• Ahead of its time
• Like John Cage's music
• In the arts, radically new and daring
• Unorthodox, untraditional leaders
• Like the work spelled out by the circled letters
• Like the work spelled out by the shaded letters
• Eye cover for the naive?
• Ahead of the times

Wiktionary Word definitions in Wiktionary
n. (alternative form of avant-garde English)