I’d like to cut the top and bottom of the waveform, leaving only the continuous middle part which is music. The peaks represent speaking, and I’m trying to isolate the audio. Is it possible to highlight the areas above and below that midsection and delete it? Thanks.

The waveform peaks actually represent both voice and music. If you clip the waves that way, you’ll get horribly distorted voices and music with holes in it.

If the work is a high quality stereo show, you might be able to use Vocal Remover.