Drew: I don't know the musical term for it per se, but Tool are masters of changing time signatures.
The song "Schism" does so 47 fucking times. FOURTY SEVEN. And it's beautiful.
Legendary for its odd timing and 47 time switches, Tool's "Schism" takes the crown this week. Here's a more detailed explanation from Wikipedia: "The song begins with two bars of 5/4, followed by one bar of 4/4, followed by bars of alternating 5/8 and 7/8, until the first interlude, which consists of alternating bars of 6/8 and 7/8.
"The following verse exhibits a similar pattern to the first, alternating bars of 5/8 and 7/8. The next section is bars of 6/4 followed by one bar of 11/8. This takes the song back into alternating 5/8 and 7/8. Another 6/8 and 7/8 section follows, and after this the song goes into repeating 7/8 bars.
"The middle section is subsequently introduced, consisting of three bars of 6/8, one bar of 3/8, and one bar of 3/4 repeating several times. At one point it interrupts with two bars of 6/8 followed by a bar of 4/8, twice. A bar of 5/8 is played before the meter switches back to 6/8 for two bars and 2/4 for one bar.
"This repeats, setting up another section: two bars of 9/8 followed by a bar of 10/8, that pattern again, and then a single bar of 9/8 followed by alternating bars of 6/8 and 7/8. The outro has alternating bars of 5/8 and 7/8, ending with alternating 6/8, 2/8 that one could interpret as pulsing with a 4/4 feel.
"The band has referred to the time signature as 6.5/8. Although many composers would use 13/16 instead, 6.5/8 is still a valid fractional time signature."