Pushing the envelope, say

• Unorthodox, untraditional leaders
• Like experimental art
• Like the work spelled out by the circled letters
• Pushing the envelope
• Like John Cage's music
• Original advantage involved in capturing king
• Those at the head of a literary movement: Fr
• Musically innovative
• Ahead of the times

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