Ho hum! I have had this Thing sitting here awaiting my attention for weeks and weeks, while I have been playing with other potential Things and other Things that I already use. Well, MIDIs. MIDI stands for Musical Instrument Digital Interface and was apparently first standardized in the 1980s. I read the wiki article and that was quite informative - maybe more information than I felt I needed.
MDIs allows all sorts of media control devices to talk to each other and computers - that's the theory and I'm sure it is probably the practice too (though not in Polyxena's life as we know it). MDI was also a major factor in getting rid of the walls of synthesizers in 1970s and 1980s rock concerts. Another result was the development of hardware and computer based sequencers, which can be used to record, edit and playback performances. These are used for mobile phone rings, and can be used for composition.
I had great difficulty with the task and didn't complete it. I thought that I downloaded the jazzmidi sequencer from www.midimart.net, but then it wouldn't install. I thought it was a free download but Tapsister thought she had to join up so maybe that was my problem. I did manage to access and save the Hallelujah chorus from Alamo5's midipage though the instructions were different to those in the discovery exercise. It was amazing to see how many midi files are around.
But, of course, as I couldn't load the sequencer I couldn't do the next part of the exercise. Ho hum! Do I care? I am glad for curiosity's sake to know of the existence of midis and midi sequencers but don't believe that I would ever use this knowledge theoretically or practically. In terms of applicability to libraries, I suppose that these files could be used in making film clips etc, but I didn't explore the copyright issues and am not sure whether this is all free for all to use.