if its has to do with your nation and its people above all, its most certainly nationalistic. classical and marching music was simply the most popular genre around the time most national songs were made, that and they had an aura of prestige surrounding them with their fine instrumentation and orchestration.
rock and guitar is quintessentially white, requiring refined skill to play and creativity to write unique riffs, which is why its popularity has dropped since the late 2000s and has been replaced by mind numbing electronic jungle nigger npc music that cant even be played on real instruments. jazz has a strange history, but it could also be considered white due to the fact that the only way to write and play it is using white invented instruments and notation. it just so happened that it became popular with blacks, which at that time had to put in much more effort than they do now to attempt to fit in in a white society, and their ability to play and write music so well is rather astonishing. it simply goes to show when not held to a higher standard how far they will fall back into their natural state.
moreover, repetition of paterns are the backbone of music, being the pleasant foil to constrast with the unique parts of a song. if its only the same thing over and over with no further development of the song, it simply becomes a tribal background noise, or rather, nigger music.
just looked up tors vrede, absolutely based and amazing, but the only two songs i can find in english are remember the fallen and unite, wish there were more but they look censored to shit