Who invented rhythmic value names based on fractions of a measure of 4/4 music?

Question

In American music a Semibreve is called a "whole note". Here it states that the name "whole note" comes from a German expression (ganze Note):

In the world of music, you may encounter different names for the many notes used. The U.S. and U.K. standard terms differ, but the U.S. names — which were originally translated from the German names for the notes because so many German composers immigrated to the United States in the 19th century — are more universally standard. The U.K. names are also used in medieval music and in some classical circles

Source: http://www.dummies.com/art-center/music/music-theory-for-dummies-cheat-sheet/

=> Is it a German invention that a Semibreve is taken as a reference value and called "whole note"? Who is the inventor of this terminology?

It causes some logical problems in time signatures other than 4/4.

=> Why don't we call a Crotchet a "whole note"?

Also see http://www.studybass.com/using-the-site/american-english-music-terminology/

Answer 1

I think there are two questions here; one has already been answered, but the other—"where does the term semibreve come from?"—I'll try to answer here. (But as shown in the comments, I may have misunderstood your question; I apologize if so.)

It is not a German invention, at least not in the way that the excerpt implies.

The notion of a "semibreve" dates at least to the work of John of Garland in his De mensurabili musica ("On measured music") of approximately 1250. From the information we have, Garland was likely an instructor at the University in Paris.

Within Garland's note shapes (and note names), he included a "semi brevis." But this was early rhythmic notation, and one of its quirks is that it was highly context-dependent; the same notation in one work may suggest something rather different in another.

Furthermore, this early in history, rhythms were divided in threes to reflect the perfection of the Holy Trinity. It wasn't until approximately the 14th century with the ars nova ("new art") composers and theorists like Jehan des Murs and Philippe de Vitry that we begin seeing more and more duple divisions of note values.

All of this to say: it is likely true that German immigrants had an impact on American rhythmic terminology. But this terminology did not originate with the Germans, but rather with authors of several nationalities many centuries earlier.

Answer 2

Stuff started rather with mensural notation where the principal "beat" tended to be a semibreve. When shorter notes had to be used, stems were used, then flags were invented. There was an increasing inflation of shorter notes and people became more comfortable with them and used to them. The original durations, clefs, and keys of pieces, typically from early Baroque and earlier, are sometimes indicated in "incipits" at the beginning of pieces. Sometimes even stuff as late as Baroque is retained in this notation, particularly meters like 3/1 (which usually is a fast triple meter).

So basically this is the outcome of subdivision inflation without people wanting to redefine terms at any particular point of time (somewhat like "permanent daylight saving time" adopted by some countries/states which makes less logical sense than just everybody agreeing to get up one hour earlier but is easier than to get everybody to agree).