Taking the key, gets out a roll of money (6)
I believe the answer is:
dollar
'money' is the definition.
(I know that Dollar is a type of Currency)
'taking the key gets out a roll' is the wordplay.
'taking' indicates putting letters inside.
'the key' becomes 'd' (musical key).
'gets out' is an anagram indicator (the letters get out of order).
'a'+'roll'='aroll'
'aroll' with letters rearranged gives 'ollar'.
'd' put within 'ollar' is 'DOLLAR'.
'of' is the link.
(Other definitions for dollar that I've seen before include "US monetary unit" , "Standard monetary unit of many countries" , "US currency" , "Monetary unit - town in Clackmannanshire" , "Economic factors deployed as 'soft power'" .)