Related Clues:

• Quatrain rhyme scheme
• Biblical ''father''
• 'Mamma Mia!' inspiration
• 'Mamma Mia' foursome
• '70s pop quartet
• Acronymic pop group name
• ''Mamma Mia'' group
• "Fernando" pop group
• The Old World
• Group with Benny and Bjorn
• "Mamma Mia!" group
• Quartet named for its members
• Palindromic Swedish icons
• ''Take a Chance on Me'' singers
• ''SOS'' group