Thrice is an American experimental post-hardcore band. They are well-known for using unusual song structures and time signatures. Their recent love affair with Russian Circles has brought in more post-rock influence. Thrice are a good part of the reason I got into prog.
Examples to consider:
from Identity Crisis (Early Thrice, generally just punk/hardcore)
Nothing, because Identity Crisis sucks.
from Illusion of Safety (Thrice finds their voice, references literature constantly)
"Where Idols Once Stood" (Unusual structure)
"A Living Dance Upon Dead Minds" (alternating 7/8 and 8/8 time signatures, chorus is in 6/8 rather than 4/4 for the last go)
"Deadbolt" (dispersed measures of 7/16, unusual structure, and count that piano outro)
from Artist in the Ambulance (Illusion of Safety part II)
"Cold Cash and Colder Hearts" "
Hoods on a Peregrine" and "Melting Point of Wax" (in 5/8 and 6/8)
"Silhouette" and "Paper Tigers" (in 6/8 and 7/8)
"
Blood Clots and Black Holes" (measure and sections of 7/8 throughout, ending has measures of 8-5-8-6-8-7-8-8)
"
The Abolition of Man" (Structure? What structure? 7/8 here and there)
from Vheissu (Thrice calms down a bit, but still explodes violently on occasion)
"
Between the End and Where We Lie" (Borrows from post-rock and electronica; chorus is in 7/8 and 9/8)
"The Earth Will Shake" (Folk influences, 7/8 pre?chorus, also mixed 4/4 and 3/4)
"Atlantic" (Nothing really, I just like the song. Maybe some post-rock or something. Whatever.)
"Hold Fast Hope" (5/4, and God forgive me, reminds me of Zeuhl. That is a bad thing.)
from The Alchemy Index Part I (Fire) (Thrice does what Thrice has always done)
"Firebreather" (If you count this right on your first go, you've been listening to way too much Meshuggah)
"Backdraft" (5/4, chorus is alternating 5/4-7/4)
You get the idea.
from The Alchemy Index Part II (Water) (Thrice plays electronica and tributes to Russian Circles)
"Open Water" and "Lost Continent" (Blatent post-rock rips)
"
Night Diving" (Russian Circles could have written this and nobody would have been surprised)
"
The Whaler" (Reminds of The Album Leaf, but in 5/4)
And as a preface,
prog-related is not prog. Let the debate begin!