Crossword puzzle clue "common refrain that's a hint to this puzzle's theme"

Common refrain that's a hint to this puzzle's theme

Hint (and a hint to this puzzle's theme)

Puzzle invented by Lewis Carroll (and a hint to this puzzle's theme)

Refrain from Dorothy and hint to the theme

Simon & Garfunkel refrain ... and this puzzle's theme

Contented sighs (and a homophonic hint to this puzzle's theme)

"Dog the Bounty Hunter" network, and a hint to the theme in this puzzle's four longest answers

2014 NBC comedy starring David Walton ... and a hint to the puzzle theme which is ___