I was thinking…didn’t nobody think why 
does the happy masks salesman own the
majoras’s mask ? Our old thread with
wrathfulmajora gave me a little idea 
that maybe he was Majora’s guardian
{ not that ‘guardian’ but maybe as Impa
is to Zelda } in another life..or maybe his
ancestors were, so he still keeps the mask 
to worship the tribe

The mask could just be passed as a familiar
tradition along with the legend in the salesman’s
family; the same case could have happened with 
the song of healing, as we all know this song
allows Link to heal the wounded souls and turn
them into a mask but didn't this god { we think
is the fierce diety } made the demon turn into a
mask while making him dance ? The song could 
be also known as the song to make majora rest

My point is; maybe the salesman isn’t just the
'happy masks salesman’