Quote from der butz :

Their music is sometimes listed as "mathcore"... don't know why this is so. Probably because sometimes you have to count carefully not to miss a beat

Hehe, yeah probably. Btw, the Flying Luttenbachers are pretty 'mathcore'

1.. 2.. 3.. 4..

Whitechapel
http://www.youtube.com/watch?v=LhoILecAWh4

Parkway Drive
http://www.youtube.com/watch?v=nXbPp-UPz6I

Born Of Osiris
http://www.youtube.com/watch?v=MYnDG9oTWjg

Do they count ?

Meshuggah
http://www.youtube.com/watch?v=qc98u-eGzlc

Then some Opeth to calm down
http://www.youtube.com/watch?v=lk6Q4FpW-sY (worth listening to the whole song, mmmmmany changes in there)

Those are my 2 practice songs nowadays on guitar. I'm not there yet .