Historical clue formulations

• Who quipped "God tells me how the music should sound, but you stand in the way" — 2008-06-19
• He conducted the premiere performances of "Pagliacci" and "La Bohème" — 2008-02-15
• Longtime La Scala conductor — 2007-01-12
• Former Met maestro — 2001-05-11
• Memorable Met conductor — 2000-06-30
• NBC Symphony conductor, 1937-54 — 1998-03-11