Quite often, bands that are described as melodic death metal are not genuinely melodic.
At the Gates, Age of Ruin, and In Flames are examples of genuinely melodic contributors to death metal, but in many cases, the word melodic has been applied to death metallers who -- truth be told -- treat melody like a mere afterthought and favor brutality for the sake of brutality.
Thus, it is important to stress that melody is never an afterthought on Ensiferum's Victory Songs; it is a crucial part of what the Finnish band does on a death metal/folk-metal album that, for all its intensity and in-your-face aggression, is highly musical and thrives on intricacy and craftsmanship.
There are quite a few different influences on this epic disc, ranging from power metal, thrash metal, punk, and progressive rock to European folk; in fact, Ensiferum combine their amplified guitars, bass, and drums with traditional acoustic instruments that have been used in Scandinavian folk for many years.
The thing that makes Victory Songs relevant to extreme metal isn't so much the song structures as the vicious lead singing of Petri Lindroos, who replaced former lead singer Jari "Arbaal" Mäenpää and has worked out nicely for Ensiferum.
Lindroos is usually mindful of metalcore's tortured screaming more than death metal's deep "cookie monster" growling, and extreme singing dominates the album.
But if Victory Songs contained nothing but clean vocals, Ensiferum would pretty much sound like a faster, thrashier version of Manowar, Savatage, or Iron Maiden (with more of an interest in traditional European folk instruments).
And if Victory Songs sounds somewhat Celtic at times, that's because Scandinavian folk was a major influence on Celtic music thanks to the Vikings, who invaded the British Isles many centuries ago.
Victory Songs is an excellent, consistently rewarding demonstration of how death metal can, in fact, be truly melodic.