Was surprised to see there wasn't a thread on this equation-riddled genre, and the post-rock thread is 10+ years old (plus math rock is also very distinct in style) so I thought I'd make one.
Math rock is a style of indie rock that emerged in the late 1980s in the United States. Math rock is characterized by complex, atypical rhythmic structures (including irregular stopping and starting), counterpoint, odd time signatures, angular melodies, and extended, often dissonant, chords.
From the Cab's second album, "Don Caballero 2":
If you want a heavier album I recommend For Respect, which came out before 2. For an easier listen, try American Don.
And a personal favorite from the defunct Chicago group Ghosts and Vodka:
Some of the members went on to join or form other bands, such as Owls and Joan of Arc.
Post your recommendations/favorite groups below!