Old American making some curtain calls (4)
I believe the answer is:
inca
'old american' is the definition.
(the Inca were a South American people)
'some curtain calls' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'INCA' is hidden within 'curtain calls'.
'making' acts as a link.
(Other definitions for inca that I've seen before include "Original Peruvian" , "lived in Peru" , "Native Peruvian" , "Ancient civilisation of Peru" , "Former emperor" .)