If the other man "borrowed" the locksmiths tools and returned them after using them, yes. Without the band originally performing and recording the song, you'd have an empty sound file. You can't take the original performance, and that the recording contains the essential value of the performance, out of the equation. If you sneak into a concert, is the theft that you occuplied a seat that you didn't pay for or that you listened to music you didn't pay for? And would you even be sneaking into the concert hall if there were no performance only to enjoy the lights, the seat, and the air conditioning?
That removes potential value in the service performed, yes, but it doesn't remove the value of the actual service, and removing potential value isn't illegal, and isn't considered theft).
But it is benefitting from the labor and the essential value of that labor without reproducing that labor yourself. If a medical lab spends $5 billion dollars researching and testing a drug, do you think that the value of a pill lies only in the value of the specific chemicals in that pill? If you are handed a copy of the formula for the drug, don't you think it would be theft to benefit from those $5 billion dollars of research and testing so that you could charge a 10 cents a pill, the actual chemical value of each pill?
With a copied song, the IP isn't stolen, and the materials and services used in creation of the copy isn't the owners (it's the property of that who copied it).
But the effort put into writing, performing, recording, and promoting that song is benefitted from without compensation. The music sharer did not expend that effort, the band did. And without that effort, there would be nothing to copy. If I ask a teenager to mow my lawn with some gas that I provide and then refuse to pay them, I haven't stolen anything physical from them. I haven't taken away their ability to mow someone else's lawn. I haven't stolen their lawnmower. I haven't deprived them of any material benefits. But I have benefitted from their labor without compensation.
Without the labor of the musicians, there would be no music. The labor was exerted specifically to produce that music. You are benefitting from the fruits of that labor and, in the absence of that labor, there would be nothing for you to benefit from. So why doesn't the musician deserve compensation for their labor? There labor does not produce any tangible product. The sole value of it lies in listening to and enjoying it and it is that value that you are taking advantage of -- without compensation.
It may (and probably does) create a copyright violation if you hand it over to another person, but it doesn't actually remove the service, goods, or the actual value of a service performed or a goods created or redistributed. It only removes a potential value, which isn't illegal in itself.
It benefits from the labor of someone without compensating them, despite the fact that they desire compensation. Using your strict definitions, if a recording studio employee were to make a copy of a prerelease recording of an album, put it out on the Internet, and, as a result, the band only sold 10 legitimate albums to pay for thousands of dollars in studio time and thousands of hours of work, no real theft would have taken place. Something doesn't seem fundamentally wrong with that to you?