Somewhere far far away, a complex algorithm selects a song for me, balancing repeats, my stated and implied preferences, the station I’ve chosen, and probably things like licencing costs.
The song is probably hosted on a Content Delivery Network that’s incredibly sophisticated to balance latency, cost at various points, etc.
The song is delivered to my phone (over any of several technologically incredible networking systems), itself an amazingly sophisticated device. The music is decoded through a really clever algorithm derived from psycho-acoustic models, then converted to an analog signal.
It’s sent down a thin cable to a very fancy pair of remarkably effective noise-canceling headphones our team were all given for a project a couple years ago.
..which are turned off.