Being performed, dance is accessible (2,3)
I believe the answer is:
on tap
'accessible' is the definition.
(I've seen this before)
'being performed dance' is the wordplay.
'being performed' becomes 'on' (eg a play may be 'on' at a particular theatre).
'dance' becomes 'tap dance' (tap dance is a kind of dance).
'on'+'tap'='ON TAP'
'is' is the link.
(Other definitions for on tap that I've seen before include "Where you may see H or C" , "where C or H is seen?" , "Readily available" , "kept in a cask" , "Available (for drinking?)" .)