The title "Man Listening to Disc" tells us a few important things. Thing one: we are back in pre-iPod days. Who listens to "discs" or CDs anymore? Do we even remember what those look like? Okay, so this poem was published in 1999—maybe not the middle ages, but long ago enough that the technology was different from what it is nowadays.
Another thing that the title tells us is that this is a poem about music. We listen to music (or at least we used to listen to music) on discs. So this is a poem about the experience of listening to music.
And finally, thing three: there's a "man" referenced in the title. That's the speaker of the poem, the dude who is having such an awesome time jammin' along to his jazz tunes as he strolls through the city. So the title is telling us that this is a poem about a guy's experience of listening to music, in the pre-iPod days. "Listening" is the big word in the title. This is a poem all about the joys and possibilities of listening to music.