Possible Clues:

• Eddy Merckx, initially behind noted leader, overtaking cyclist in the middle
• 'A Descent into the --', a short story by Edgar Allan Poe
• Upheaval as Merlot replaced with Medoc at first
• Pandemonium as married, eminent conductor's hugging student at the opening
• Whirlpool — Moslem art (anag)
• Turbulence in realm most unusual
• Ace crossing lake and medium whirlpool
• Big Eddy, top performer, clutches large mike
• “I’m a normal man with a good memory who fell into a ____ and got out of it more by luck than by virtue” (Primo Levi)
• Eminent composer accepting large maiden causes big confusion