Great deal of topless altos dancing (4)
I believe the answer is:
lots
'great deal' is the definition.
(I've seen this in another clue)
'topless altos dancing' is the wordplay.
'topless' means to remove the first letter.
'dancing' is an anagram indicator.
'altos' with its initial letter removed is 'ltos'.
'ltos' with letters rearranged gives 'LOTS'.
'of' is the link.
(Other definitions for lots that I've seen before include "Large number or amount" , "Large numbers at auction" , "Items offered at auction" , "Many - items in a sale" , "Oodles" .)