Test clothing case right for several players (10)
I believe the answer is:
orchestral
'for several players' is the definition.
(for a large group of musicians)
'test clothing case right' is the wordplay.
'test' becomes 'oral' (oral is a type of examination).
'clothing' indicates putting letters inside (some letters cover up or clothe others).
'case' becomes 'chest' (both are types of container).
'right' becomes 'r' (common abbreviation).
'chest'+'r'='chestr'
'oral' placed around 'chestr' is 'ORCHESTRAL'.
(Other definitions for orchestral that I've seen before include "Unlike chorales" , "Like the RPO" , "For a large group of musicians - her car slot (anag)" , "for the band" , "Clare Short (anag)" .)