Great poem. It is quite creative in that it goes beyond the expected poem of witchcraft, which I have encountered a lot while reading poetry pieces. The third line is repeated in each stanza, which adds to its value as it is quite melodic in its repetition, and it is, therefore, doing what is described in the line.

Now, what I don't love is the fourth line of each stanza. So, in the first stanza, you have a piper, you set out the tune for the whole poem, the witches are dancing - they are going to reveal the power soon. In the second, there is a sense that united, the coven is stronger, and they are chanting because they are going to take over soon. Lastly, there's a feeling that they will achieve glory and power, soon.

What is weak about the last lines is that they hold a lot of promise, but they do not describe much. All of them promise 'soon', which what you are saying is, that the climax of the story or the event will happen outside this poem. The last words should be striking and powerful, as I have said to others before. The 'powers' spoken about are abstract, and if the reader is shown, it could leave more impact as a poem.

Nonetheless, this was quite great; the structure and idea behind it are quite interesting. This could be a too-critical of an approach, but the poem is good in itself, especially the first two stanzas.