Ok hypothetical scenario. Lets say I want to generate a lot of key material quickly for a one-time pad. This key material will be divided up and used for many different messages in the future.
I select 50-100+ songs out of a custom playlist of all my music. The music has been converted to basic Waveform Audio File Format (.wav). The music could be a mix of rock, pop, classical, techno etc just whatever I selected.
I extract every song's raw music data out into one big file and remove null bytes. Now I have a single big file with all of the song data in it.
I randomize all of the song data so all the song data is blended together into an unintelligible sequence of bits. The user can provide some input using their mouse/keyboard which will provide some entropy into the randomizing function.
I loop through all the data in the file, taking every ~7th byte (or bit) and put it into another file which is now my new key material. This step could be altered so the user can provide a variable sample rate, e.g. they can change it to every 10th byte or 100th byte.
Now... is that file of key material sufficiently random for one-time pad use?
What about if I changed out music songs and use 10+ full length movies or TV shows instead?