The poem opens with a question: do the wicked pray for tumult? The idea is a little strange, since prayer is usually for peace, but the speaker seems to wonder whether the people we call wicked actually want chaos, and whether holiness might want it too. The "holy drum and trumpet" put sacred language right next to the sounds of war, so the line between devotion and violence starts to blur.
The middle lines give us a picture: fields full of soldiers, riding up and down. It's restless and endless, with no clear purpose or enemy. Then the poem turns to something more earthy, "the bawdy work of a tongue," and finally "that barbarous tune." Judging by these images, the speaker hears war, worship, and bawdy talk as versions of the same racket.
The mood is uneasy and quietly wry. The speaker doesn't announce an answer. Instead the poem leaves you listening to all that noise and asking who is really calling for it.