This song is written for a 7-string guitar. There are only six strings on the tab because of a limitation of the tabulature software. Also, most of the articulations and section markers, tempos, etc. are missing because of similar limitations of the software. To play the song as written in the tab you would need to tune your guitar to B,E,A,D,G,B low to high. Use your ears and you should be able to get most of it figured out. Keep in mind this is just a quick tab of the song and is missing the harmonies and textural background parts.