Guido of Arezzo (991/992 - (17 May?) 1050) was a music theorist of the Medieval era. He is regarded as the inventor of modern musical notation (staff notation) that replaced neumatic notation:
http://en.wikipedia.org/wiki/Guido_of_Arezzo
Evgeni Kostitsyn invented notation of polytempo music in the XX century. "A Guide to Engrave Polytempo Music"(24 pages) explains how to engrave page 66 of "Macondo Swing"ballet by Evgeni Kostitsyn.
- A Guide. pdf file
- Evgeni Kostitsyn. Macondo Swing. Page 66. pdf file
- Evgeni Kostitsyn. Macondo Swing. Page 66. Finale file
- The Kostitsyn Library. Finale file