#1: Theme of this puzzle 11 letters

Crossword clues for #1: Theme of this puzzle 11 letters:

TRUSTBUSTER: #1: Theme of this puzzle
NORDICCROSSES: Image on the flags of the 5 countries (and 1 autonomous region!) in this puzzle ... and a description of this puzzle's theme
LEADEROFTHEPACK: 1964 #1 hit by the Shangri-Las ... or this puzzle's theme
BIGGIRLSDONTCRY: 1962 #1 hit by the group hinted at in this puzzle's theme
RUNAROUNDSUE: 1961 #1 hit for Dion, and a literal hint to this puzzle's hidden theme
LITTLEEVA: Singer with a 1962 #1 hit that started a dance craze (and a hint to this puzzle's theme)
THE: Parts 1 and 4 of this puzzle's theme