Ostentatious display of band to secure record backing (6)
I believe the answer is:
splash
'ostentatious display' is the definition.
(as in making a splash)
'band to secure record backing' is the wordplay.
'band' becomes 'sash' (sash is a kind of band).
'to secure' is an insertion indicator.
'record' becomes 'lp' (L-P is an example).
'backing' says the letters should be written backwards.
'lp' written backwards gives 'pl'.
'sash' enclosing 'pl' is 'SPLASH'.
'of' acts as a link.
(Other definitions for splash that I've seen before include "Spatter liquid about" , "coming down of an astronaut" , "Spend freely or make wet" , "Lead newspaper story" , "Big media display -- bellyflop effect" .)