The process of revising "This Music Has Holes in It" is a matter of very fine adjustments (see section titled "The Poem's Gaps"). In order to best illustrate the development of the poem, I will present the first pages of three drafts side-by-side here and the second pages of the same drafts in the next section.
The final draft, you might note, is the shortest of the three. By and large, the process of revising this poem is a process of addition by subtraction.
2006 draft from The Baseball Field at Night manuscript