Related Clues:

• Like some modern music
• Without a key
• Unaccented
• Musically keyless
• Lacking a key, in music
• Discordant, musically
• Like much modern music
• Flat as a piano?
• Hard-to-hum
• Lacking a key center
• Lacking a musical quality
• Unmelodious
• Like Berg's opera "Wozzeck"
• Lacking a key
• Like many a Schoenberg composition