Conductors stream alternative current (7)
I believe the answer is:
maestri
'conductors' is the definition.
(I've seen this before)
'stream alternative current' is the wordplay.
'alternative' indicates anagramming the letters (an alternative ordering of the letters).
'current' becomes 'I' (physics symbol).
'stream' with letters rearranged gives 'maestr'.
'maestr'+'i'='MAESTRI'
(Other definitions for maestri that I've seen before include "Top conductors" , "leading musicians" , "great musicians" , "Famous conductors" , "Experts" .)