Possible Clues:

• Wrinkle-resistant fabrics
• 1960s group with a fabric-related name, with 'the'
• The earliest synthetic fibers
• 'The Wah-Watusi' singers
• Group with the 1963 hit 'South Street,' with 'the'
• Crease-resistant fabrics
• Group that sang the 1962 hit 'The Wah Watusi,' with 'the'
• "South Street" singers, with "the"
• 1960s group of "Wah-Watusi" fame, the ___
• 'The Wah Watusi' singers, with 'the'