Called and rushed to get key (4)
I believe the answer is:
rang
'called' is the definition.
(called on the phone)
'rushed to get key' is the wordplay.
'rushed' becomes 'ran'.
'to get' means one lot of letters go next to another.
'key' becomes 'g' (musical key).
'ran'+'g'='RANG'
'and' is the link.
(Other definitions for rang that I've seen before include "Phoned; reverberated" , "Telephoned" , "Chimed" , "Made a phone call" , "(Of bell) sounded" .)