were you familiar with the concept of nasheeds? no? i wasn't until i heard this story on NPR. here's a guardian article about the nasheeds of isis / daesh.
it's not so easy to get a plain recording of the nasheed popular as the supposed ISIS anthem, but it's worth listening to. i'm, not embedding it, because simply having in in my search history probably puts me on terrorist watchlists. here's a link, though. this version has an english translation, so you can either just listen and enjoy the catchy tune, or be appalled by the text.
then again, while daesh is not a nation, it would like to be. it's not all that long ago (on the large scale) that the US was not a nation but wanted to be. and our values and aims were no doubt repugnant to many decent people everywhere. and it's not like this is the only anthem to have violent lyrics. you know the star-spangled banner, right? those rockets and bombs are not display pieces.
and la marseillaise? yeah, throat-slitting. blood in fields.
nasheeds themselves are not the province of daesh, though. they're just meant to be hymns. of course if you have a religion i disapprove of it, but religions do produce some lovely music.
here's a pretty nasheed with some english verses.
there. now go rinse out your head.