Pianists who coach a lot of sopranos often end up playing the reduction of this work quite frequently over the years, so it's worth spending the time learning it well. Knowing the sound of the orchestra is critical when learning the reduction, as it gives you an idea not only of the instrumentation but the entire emotional scope of the work. Knoxville: Summer of 1915 is a work that can move an audience to tears when performed with honesty and simplicity.
Now I know the camera is a bit shaky and out of focus, the orchestra is perhaps a bit under-rehearsed, and the microphone is too far away to give complete clarity of audio, but I don't think you're going to find many performances of this work as committed and moving as this one. The text of this work is quite complex, so you might want to follow along with the text in order to understand this excerpt of James Agee's epic prose poem (which forms part of the introduction to Agee's Pulitzer Prize-winning novel A Death in the Family).