The songs have these experimental, instrumental parts at times while other songs have vocals and are just noisy. It's the contrast between the two which makes this album so special. At one point, you'll hear feedback being manipulated or electronic beeps. But then there are also songs which could be somewhat punk, somewhere along the lines of Cheap Trick or Jimmy Eat World.
Perhaps my favorite song though is called "El Agujero (Morente)" and that is because it represents in many ways both sides of this album. It has that raucous vibe to it but also remains instrumental so it kind of shows that the vocals don't always need to be in place for this one to kick down walls. And not just in a physical sense could I imagine Meus kicking down walls (think of The Who) but also in the sense that this music might change your perception of rock n roll which is never a bad thing.