Possible Clues:

• Fleetwood Mac’s “Walk ___ Line”
• Walk __ line
• 'Walking on ___ Line' (Huey Lewis and the News hit)
• "It's __ line between love and hate": 1971 song lyric
• Walk __ line (tread carefully)
• Dylan's "Ballad of __ Man"
• Fleetwood Mac's 'Walk ___ Line'