Related Clues:

• Modern composer's arrangement of bars using four notes
• Caught, then time for pen
• John --, US composer of experimental music
• Start of crossword takes a long time in 3D grid
• Century's a long time in prison
• Pen impounded by narcotic agent
• American behind bars in prison
• Detains The Animals going around Cambridge
• 'Left Behind' actor
• Asset in a castle siege
• Ditch used as a defence
• Vehicle test round a deep ditch
• Confined enclosure
• Drawbridge locale
• All-round defence in depth?