V8 V8, since you are going to be the one running this, please apply your editorial skills and help me pick the format for this. I think after reading @studmissile and @NorioDS's comments, my vote is for the 4-note challenge, but in the normal competition format. This gives everyone enough time to try, it doesn't limit anyone to acoustic or electric and it will hopefully bat @Norios's concern about lining up with the newsletters.
Agree with @studmissile, this will require some fretboard study and some creativity. The main riff to Shine on You Crazy Diamond is only 4 notes, so should be easy right?
Will leave it up to you and @NorioDS to figure out dates and things so they sync with the newsletters.