 The two based their edition on previous work by Munich philologist Wilhelm Meyer, who discovered that some pages of the "Codex Buranus" had mistakenly been bound into other old books.He also was able to revise illegible portions of the text by comparing them to similar works.About one-quarter of the poems in the "Carmina Burana" are accompanied in the manuscript by music using unheighted, staffless neumes, an archaic system of musical notation that by the time of the manuscript had largely been superseded by staffed neumes.