@atlasanarchy Here is "Dethklok - Skyhunter":
D-EFA-G-
A-CDA-G-
G and the first and last A are high, the second A and all other notes are low. The song actually contains a combination of sharp and flat notes that cannot be accurately recreated as a town/island tune. This was as close as I could get with all natural notes. The C should really be a C sharp for it to be 100% accurate, but unfortunately that's just not possible in Animal Crossing.
The part of "Metalocalypse - Pickles Rehab Song HQ [ReMastered] + Skyhunter" that you requested isn't entirely melodic because of how the singer sort of slides his voice down, hitting every note on the way and a lot of tones in between notes that aren't really notes, so there isn't any way to really recreate that accurately as a town/island tune. If there's a different part of the song you'd like me to try, just let me know.
@WanTjhen777 Here is "Pokémon Anime BGM - Lilycove City (2002~2005(AG)-M04)":
CBC---D-
D---E-E-
--D-D---
All the high notes or all the low notes will work. The timing of the original song means that the whole musical phrase can't fit into two lines, which is all town/island tunes have. So I made it be three. You can either use two of the lines as they are, or you can try removing sustain lines - to make more of the notes fit in, but this will change the timing andmake the song sound different. So you can make it be however you like.