Alvin's or Ziggy's magical quality? (8)
I believe the answer is:
stardust
'magical quality?' is the definition.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for stardust that I've seen before include "In Woodstock we are this" , "that could blind one to reality" , "Imaginary particles blinding someone to reality" , "Singer < and song" .)