Or you could get 4 minutes of stereo music, Opus@40Kbps or half an hour of speech Opus@6Kbps - (Vinyl LP seems to be more efficient and simpler for that).
Or the best 25 classical pieces in MIDI, for example Beethoven Symphony #5 in C minor is a 322 KB midi file (compressed 60 KB). With compressed ABC or Alda notation you could even fit 10 times as much. Or you can just read the ABC and automatically 'hear' the music in your head (is there a similar notation for human movement or dance i wonder...).
Even so perhaps a better and more cost effective system is microfilm, here an example of the bible printed on a 2 inch film: http://www.amazon.com/Microform-Bible-Much-Like-First/dp/B00... - you don't need a computer, just a lensing system. It has one downside, the blind cannot use this unless you'd make an OCR to TTS or braille display converter on top of it.
Or as described in the book Mindhacker you could use Dutton Speedwords/Briefscript word abbreviations preferrable tailored to Esperanto to double the text on the microfilm or on your handwritten A4. https://github.com/leonardoce/bumot