Screen background of jazz pianist entertaining Pulp (9)
I believe the answer is:
wallpaper
'screen background' is the definition.
(I've seen this before)
'jazz pianist entertaining pulp' is the wordplay.
'jazz pianist' becomes 'waller' (I can't explain this - if you can you should believe this answer much more).
'entertaining' is an insertion indicator (inviting in, as for dinner).
'pulp' becomes 'pap' (both can mean worthless or trivial stuff).
'waller' enclosing 'pap' is 'WALLPAPER'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for wallpaper that I've seen before include "Screen background" , "Pasted covering" , "Mural decoration" , "Bland and unoriginal stuff - for decorating" .)