Macbeth - Act 5 Scene 6

Dunsinane. Before the castle.

Drum and colours. Enter MALCOLM, SIWARD, MACDUFF, and their Army,
with boughs

MALCOLM
Now near enough: your leafy screens throw down,
And show like those you are. You, worthy uncle,
Shall, with my cousin, your right-noble son,
Lead our first battle; worthy Macduff and we
Shall take upon 's what else remains to do,
According to our order.

Siward's words here could be a public address to Malcolm and the army, or they could be a more private conversation with his son, which would help emphasize the importance of Young Siward.

The trumpets have been present throughout this play, sounding retreats and announcing arrivals, and now they heighten the drama of the this climactic charge.

SIWARD
Fare you well.
Do we but find the tyrant's power to-night,
Let us be beaten, if we cannot fight.

MACDUFF
Make all our trumpets speak; give them all breath,
Those clamorous harbingers of blood and death.

Exeunt