Plus, while films and television can be affecting and emotionally moving, you typically sit down, watch them for an hour or five, and move on. Music permeates our daily lives and by its nature can get tied up in all sorts of complex emotions and memories.
There are movies that have affected me profoundly but I'd have to watch them again in the right circumstances and mood to even hope to be similarly affected a second or third time. But there are songs and albums that I'd argue will always get an emotional reaction from me barring some weird scenario where I had to listen to them on repeat for days until they were worn out.