Instrument used in samba and rumba (4)
I believe the answer is:
drum
'instrument' is the definition.
(I know that Drum is a instrument)
'in samba and rumba' is the wordplay.
'in' indicates the answer is hidden within the clue.
'DRUM' can be found hidden inside 'samba and rumba'.
'used' is the link.
(Other definitions for drum that I've seen before include "Introductory beats" , "See 18" , "one will be beaten" , "found in the kitchen?" , "Percussion instrument" .)