Breasts shown by the old woman in old musical (6)

'breasts' is the definition.
The definition and answer can be both body parts as well as being plural nouns.
Maybe they are linked in a way I don't understand?

'the old woman in old musical' is the wordplay.
'the old woman' becomes 'ma' (I've seen this in other clues).
'in' is an insertion indicator.
'old musical' becomes 'mame'.
'ma' going inside 'mame' is 'MAMMAE'.

'shown by' is the link.