Samurai film ‘Revenge’ (Adauchi)

I know this is a long shot, but during this famous film the main protagonist can be seen singing a 'Samurai war song' (I can't find a youtubeclip of it) The lyrics are translated as

The conch shell sounds
Our sword at our sides
Spears at hand,
Matchsticks on our backs,

The time draws nigh.
Towards the field of battle we advance,
We shall not look back once.

Saddles on our horses
Banners on our saddles
The wind in our banners
The clouds on the wind.

The time draws nigh,
We journey to the afterlife!

Does anyone know if this is a real song, its title etc? Ai suggests it's called 'Dokan-bushi' but it's a bit of a blind alley.

That should be 'matchlocks'