Later on, composer Elliott Carter, in the fifties, began polymetric experiments in his string quartets that inevitably amounted to polytempic behavior by nature of several competing lines at different surface speeds.
At around the same time, composer Henry Brant expanded on Ives's The Unanswered Question to create a spatial music in which entire ensembles, separated by vast distances, play in distinct simultaneous tempi.
[citation needed] Today's composers are employing polytempi as a compositional strategy to create total and complete independence of line in polyphonic music.
Composers such as Conlon Nancarrow, David A. Jaffe, Evgeni Kostitsyn, Kyle Gann, Kenneth Jonsson, John Arrigo-Nelson, Brian Ferneyhough, Karlheinz Stockhausen, Frank Zappa, and Peter Thoegersen have used various methods in achieving polytempic effects in their music.
The idea was then proposed by Iannis Xenakis in the early seventies and more recently by Italian born composer Valerio Camporini Faggioni [3] using synthetic and software devices.