Possible Clues:

• Geometrical figure - musical instrument
• Figure
• Large tin (anag.)
• Figure how one might attempt to fish, by the sound of it, here
• Does it provide a discordant note when eternally in a marriage
• Article in humorous magazine describes outstanding feature of Falstaff
• Figure it's something to play
• Shape has little right with one getting into mess
• Musical shape
• Three-sided percussion instrument