Notice the double-tracking techniques used sparingly to bolster the choruses. Textural Dissonance
However, a multitrack is not a mix.
A verified In Utero multitrack for a song like Very Ape will contain exactly 8 discrete tracks (Drums L, Drums R, Bass, Guitar 1, Guitar 2, Vocals, Backup Vocals, Room Mic). A fake might only have 4 or 5 merged stems. nirvana in utero multitracks wav verified