The 20th-aniversary super-deluxe edition of Nirvana’s third and final studio album, In Utero, features the original mix along with Steve Albini’s never-released mixes for the singles “Heart Shaped Box” and “All Apologies” placed alongside the Scott Litt remixes that appeared on the album. Plus there's a 2013 mix of the album that further intensifies the sound. The Albini mix was raw and deliberately unpolished, while the new mixes bring out tonal colors no one’s heard before. All of these versions should make it fun for obsessive fans to hear the differences and should quell purists' dissent. Then there are the rare b-sides, demos (including instrumental takes for karaoke fans and Dave Grohl’s 1990 solo demo of his earliest composition “Marigold”), the recently unearthed instrumental “Forgotten Tune,” and the full-length Live & Loud show from Seattle’s Pier 48 on Dec. 13, 1993, which features the final Nirvana lineup with second guitarist Pat Smear. Incredible and intense.