Soundgarden finally hit on something with 1994’s Superunknown.

It helped that the rest of the nation finally caught up with their sludgy mix of Seattle punk and Black Sabbath-inspired doom metal. But after three albums of increasingly heavy and thundering sounds, Soundgarden reached No. 1 with a record that threw an artsy expansion pack in there.

So when they followed up Superunknown on May 21, 1996, with Down on the Upside, it was only in the natural order of things that would lead them to continue on this experimental path.

Down on the Upside downplayed the band’s heavier tendencies and replaced them with mandolins, piano and splashes of psychedelia that sounded weightier than any of the down-tuned guitars found on the band’s earlier and more metal-influenced albums.

Not everyone in Soundgarden was happy with this move. Tensions between singer Chris Cornell and guitarist Kim Thayil got to the point where pretty much everyone knew that this could be the group’s last record.

But for all the changes and mixing up, Down on the Upside doesn’t sound all that different than Superunknown, which began the group’s migration toward this direction. The band co-produced the record with Adam Kasper, who worked as an assistant engineer on Superunknown.

Watch Soundgarden's 'Burden in My Hand' Video

So the album’s best songs – "Pretty Noose," "Rhinosaur," "Ty Cobb," "Blow Up the Outside World," "Burden in My Hand" – sound like extensions of Superunknown with some modifications.

The album debuted at No. 2 and indeed turned out to be Soundgarden’s last until 2012’s reunion record, King Animal. It sold a million copies and spawned four singles, three of which reached the rock and modern-rock Top 10 charts. "Pretty Noose" and "Burden in My Hand" even cracked the Top 40.

Today, Down on the Upside stands as Soundgarden’s most ambitious record. But back when it came out, it sounded like it was tearing them apart. And it eventually did.

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