Meditation is more than just relaxation. It's about a state of mind. About being in the present moment, letting go, looking inward and reflecting about oneself. I don't think you do any of those things when just relaxing while listening to music.
Also,
> I am perfectly capable of relaxing and unburdening my mind, but it just ain't happening during a normal workday with deadlines and badly defined business processes.
That means you are not perfectly capable of relaxing your mind.