Small beer, holding English instrument (6)
I believe the answer is:
spinet
'instrument' is the definition.
(spinet is a historical type of musical instrument)
'small beer holding english' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'beer' becomes 'pint' (beer is typically served by the pint).
'holding' indicates putting letters inside.
'english' becomes 'e' (abbreviation).
'pint' going around 'e' is 'pinet'.
's'+'pinet'='SPINET'
(Other definitions for spinet that I've seen before include "Small 12" , "Instep (anag)" , "Type of early harpsichord" , "organ" , "Early keyboard instrument" .)