Today marks the 30th Anniversary of the release of Soundgarden’s blockbuster album Superunknown. It debuted at #1 on the Billboard 200 album chart, edging out Nine Inch Nails’ landmark album The Downward Spiral (released the same day), and it went on to sell nearly 10 million units. Soundgarden collected two Grammys from the album, one for the superb rocker “Spoonman,” and the other for the haunting classic “Black Hole Sun.” The latter is probably Soundgarden’s best known song. An enduring symbol of singer Chris Cornell’s ingenious songwriting, it’s enigmatic, foreboding, triumphant, and intoxicating — all at the same time.