Heart-Shaped Box was released as a single on Nirvana's album "In Utero" in 1993. This song's in drop D tuning which is always interesting to play in. It has some cool arpeggiated riffs, which is atypical of Nirvana's usual power chord centric guitar parts. Even though you still play power chords in the verses, they're arpeggiated which gives them a bit more movement and keeps things interesting. In the chorus, you switch from arpeggios to block chords with a high pitched bend that sounds almost like two guitar parts. This song uses a lot of bending, palm muting, and down picking techniques, as well as slurs and pulloffs, so there's a lot to practice in this one.