Polyrhythm is the simultaneous use of two or more conflicting rhythms, that are not readily perceived as deriving from one another, or as simple manifestations of the same meter. Concerning the use of a two-over-three (2:3) hemiola in Beethoven's Sixth String Quartet, Ernest Walker states, "The vigorously effective Scherzo is in 3/4 time, but with a curiously persistent cross-rhythm that does its best to persuade us that it is really in 6/8. A simple example of a cross-rhythm is 3 evenly spaced notes against 2 (3:2), also known as a hemiola. Two simple and common ways to express this pattern in standard western musical notation would be 3 quarter notes over 2 dotted quarter notes within one bar of 6/8 time, quarter note triplets over 2 quarter notes within one bar of 2/4 time. Other cross-rhythms are 4:3 (with 4 dotted eight notes over 3 quarter notes within a bar of 3/4 time as an example in standard western musical notation), 5:2, 5:3, 5:4, etc. Polyrhythm is a staple of modern jazz. Although not as common, use of systemic cross-rhythm is also found in jazz. In 1959, Mongo Santamaria recorded "Afro Blue," the first jazz standard built upon a typical African 6:4 cross-rhythm (two cycles of 3:2). The famous jazz drummer Elvin Jones took the opposite approach, superimposing two cross-beats over every measure of a 3/4 jazz waltz (2:3). This swung 3/4 is perhaps the most common example of overt cross-rhythm in jazz. In 1963 John Coltrane recorded "Afro Blue" with Elvin Jones on drums. Coltrane reversed the metric hierarchy of Santamaria's composition, performing it instead in 3/4 swing (2:3).