InterAction Magazine Ken and Roberta Williams provide PDFs of every issue of Sierra Newsletter / Sierra Magazine / InterAction, from June 1981–Spring 1999. Not that anybody much cares about them past 1992-ish.
Wikipedia: Hundred twenty-eighth note Turns out they're a thing. Beethoven used them, as did Mozart. Much like the entire skill of drumming, I imagine that I lack the ability to play these.