Person in charge succeeded initially in pitch (4)
I believe the answer is:
tsar
'person in charge' is the definition.
(I've seen this before)
'succeeded initially in pitch' is the wordplay.
'initially' indicates taking the first letters.
'in' means one lot of letters goes inside another.
'pitch' becomes 'tar' ('tar' can be a synonym of 'pitch'**).
The initial letter of 'succeeded' is 's'.
's' put into 'tar' is 'TSAR'.
(Other definitions for tsar that I've seen before include "Alexander and Nicholas held this title in Russia" , "Supreme authority" , "Absolute ruler" , "Peter the Great, for example" , "Powerful man" .)