Possible Clues:

• Singing syllables
• Singers' refrains
• Much of ''Deck the Halls''
• What people sing when they don't know the words
• Singers' syllables
• Former U.S. soccer star Alexi
• Common nonsense lyric syllables
• National Soccer Hall of Famer Alexi
• Singer's syllables
• Lots of 'Deck the Halls'