Sound from American serving in bar (7)
I believe the answer is:
logical
'sound' is the definition.
(I've seen this in another clue)
'american serving in bar' is the wordplay.
'american serving' becomes 'gi' (GI is a term for a US soldier).
'in' is an insertion indicator.
'bar' becomes 'local' (I've seen this before).
'gi' inserted inside 'local' is 'LOGICAL'.
'from' acts as a link.
(Other definitions for logical that I've seen before include "Deductive" , "Correctly thought out" , "In accordance with reason" , "Well-reasoned" , "Based on reason" .)