Historical clue formulations

• Quintet instrument — 2017-09-14
• Itzhak Perlman's instrument — 2016-03-28
• Sound in "Eleanor Rigby" and "Yesterday" — 2015-11-29
• Isaac Stern's instrument — 2010-11-30
• "A table, a chair, a bowl of fruit and a ___; what else does a man need to be happy?": Albert Einstein — 2009-03-22
• String in a string quartet — 1998-04-22
• Instrument played by 24-Down — 1997-02-15