Singers from Switzerland or America (6)
I believe the answer is:
chorus
'singers' is the definition.
(chorus can mean a group of singers)
'switzerland or america' is the wordplay.
'switzerland' becomes 'ch' (short for Confoederatio Helvetica, its Latin name).
'america' becomes 'US' (United States).
'ch'+'or'+'us'='CHORUS'
'from' is the link.
(Other definitions for chorus that I've seen before include "Group singing together" , "Sing together" , "Band of singers and dancers" , "Speak in unison" , "Vocal composition" .)