Historical clue formulations

• See 18-Down — 2014-03-26
• The "N" of PIN — 2012-12-17
• Cell assignment — 2010-02-26
• "Sorry, Wrong ___" — 2009-04-21
• Repertoire component — 2008-04-30
• Karaoke selection — 2007-03-27
• See 1-Across — 2006-09-23
• Musical selection — 2004-03-18
• Show song — 1996-02-20