do you know how the staff developed?

first off peeps where writing little signs on top of the lyrics to indicate APROXXIMATELY how to sing them. those signs where called "Neumen". those signs where mor like an indication for rythmics than for melody. then, after a while (i´ll leave away all the years and names this time - just wanna give a short survey) someone drew a horizontal line as an index for pitch. some "notes" where on the line, some where above, some below. of course this was also not very pricise. then, one beautifull day guido d´arezzo worked his way towards a five line system where it was easier. you could write a not on or between the lines,thus indicating its pitch. but then someone discovered, that you can divide the intervalls to get halftones that work perfectly aswell in music. but what now? the keys on the ancient "pianos" where all white.. there were only five lines in the note system... where to put these "new" tones? knowing that most of this developement took place in monastaries, you can imagine that those fellas did hardly want to change something that has been there for ages. so they searched for other solutions. the black keys on the keyboard (they somehow look less important then the white ones, dont they?) and the "b" and "#" and the diminished and augmented intervalnames. why easy when there is a difficult way? *LOL*