The mesmeric musician Vangelis is stupefying (8)

I believe the answer is:

svengali

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'the mesmeric musician' is the definition.
'svengali' can be an answer for 'musician' (I've seen this before). I am not certain of the 'the mesmeric' bit.

'vangelis is stupefying' is the wordplay.
'vangelis' anagrams to 'SVENGALI'.
Though, I am unsure how this is indicated.

Can you help me to learn more?

(Other definitions for svengali that I've seen before include "Leavings of a fictional evil hypnotist" , "Evil person - leavings (anag)" , "Person who controls another's mind - musician and evil genius (created by George du Maurier)" , "(controlling person)" , "Control freak" .)

I've seen this clue in The Telegraph.

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