Westworld: What's the song in the season 2 trailer?

There's a new trailer for the second season of Westworld, and it might prompt you to dig out your favorite flannel.

The creepy trailer is set to a lush and dynamic orchestral version of Nirvana's "Heart-Shaped Box" by the show's composer Ramin Djawadi. We're not exactly sure how Kurt Cobain would feel about it, but we have a feeling he'd be impressed.

Cobain wrote the original in early 1992, less than a year after Nirvana (which also included bassist Krist Novoselic and drummer Dave Grohl) burst out of Seattle with their genre-defining grunge masterpiece Nevermind. It was an infamously turbulent time for the band, as Cobain struggled to cope with his sudden fame. He had forgotten about the song for a while, but he began to work on it again when he and his new wife, Hole frontwoman Courtney Love, moved to a house in the Hollywood Hills. It became the lead single on Nirvana's third and final studio album, In Utero, which was released in 1993 — a year before Cobain committed suicide.

As with most Nirvana songs, "Heart-Shaped Box" features lyrics that are intentionally vague and more about imagery and sounds than any specific underlying theme. Cobain told biographer Michael Azerrad that it's about children with cancer, which would be supported by the morbid line, "I wish I could eat your cancer well." However, there's reason to believe the song is actually about Courtney Love. When Lana Del Rey covered it in 2012, Love tweeted to her, "You do know the song is about my vagina, right?"

Whatever the inspiration, the song does seem to lend itself to the dystopian themes of Westworld. While Djawadi's orchestral take doesn't feature any of the lyrics, anyone who lived through the '90s can probably still hear them. One line in particular, "I've been locked inside your heart-shaped box for weeks," sounds a lot like something that Dolores (Evan Rachel Wood) might be thinking as she becomes increasingly aware of the reality of her caged existence. The song also vacillates between delicate verses and rage-filled choruses, and that schizophrenic nature could easily apply to the mind of Dolores.

Of course, this isn't the first time Djawadi (who is also the composer for Game of Thrones) has reimagined a relatively contemporary song for Westworld. The soundtrack to the first season includes piano or orchestral covers of Soundgarden's "Black Hole Sun," The Rolling Stones' "Paint it Black," and several Radiohead covers including "Fake Plastic Trees," "No Surprises," and "Exit Music (For a Film)."

It's really an ingenious way to infuse familiar melodies into the strange and synthesized landscape of Westworld where everything is familiar, but altogether different. And if this take on "Heart-Shaped Box" is any indication, we should expect plenty more musical reference points in season 2.

The second season of Westworld will premiere on HBO on April 22. Meanwhile, revisit the Nirvana song and listen to Djawadi's complete cover in the videos below.