The answer here is deceptively simple: Polytempo.  There are other names, such as multi-tempo, polytemporal, and others, but they all describe the same phenomena.

Here is a link for further reading on Wikipedia.

For a list of composers that have used this technique, as well as the pieces in which this technique was used, check out this page and look under "Compositions".



I want to clarify for everyone that Polyrhythm and Polymetric are both incorrect here.  Polyrhythms are multiple, independent rhythmic lines (typically ostinatos) that can form a hemiola or hemiola-like effect in music.  Polymeters are ways of organizing the beat.  Tempo is the speed of the beat, not how it is organized, or the rhythms that it defines.

Here is a wonderful Q/A from this very website that addresses the difference: Polymeter vs Polyrhythm 

What is it called when a music has two concurrent tempos
I had an EBS volume of 30GB that was mounted as the rootfs for a ubuntu server. Due to space concerns I had to increase the size of the volume to 50. So I carried out the following steps:


  
  Take a snapshot of the EBS volume.
  Created a new EBS volume of 50GB.
  Restored the snapshot to the new volume.
  Power off my EC2 instance.
  Unmounted my old volume and mounted my new volume.
  


Every thing works fine. But when I do a df -h I get this:

Filesystem Size Used Avail Use% Mounted on
rootfs 30G 27G 1.1G 97% /
devtmpfs 1.9G 112K 1.9G 1% /dev
tmpfs 1.9G 0 1.9G 0% /dev/shm
/dev/xvde1 30G 27G 1.1G 97% /


And when I do fdisk -l I get this:

Disk /dev/xvde1: 53.7 GB, 53687091200 bytes.


Could some one help me with this?
