Last week, three Tool albums received acknowledgment for having sold another million copies apiece in the United States in an update to the veteran post-metal band's multi-platinum certifications by the Recording Industry Association of America (RIAA).

The group's debut studio album, 1992's Undertow, plus Lateralus (2001) and its follow-up, 2006's 10,000 Days, each ascended one more rung on the multi-platinum ladder on April 15. The bump undoubtedly comes from Tool albums' newfound availability on streaming services. Just before the August 2019 release of the group's Fear Inoculum, their back catalog was unavailable to be streamed.

In the April RIAA update, Undertow went from being 2x multi-platinum to 3x multi-platinum. It was the album's first RIAA certification refiguring in 20 years, last reaching double-platinum status in May 2001. It went platinum the first time in September 1994, after achieving the gold (500,000 in U.S. sales) award in December 1993.

Lateralus followed a similar path. The 2001 album also went from 2x to 3x multi-platinum on April 15. It first hit double platinum in August 2003 after going gold and platinum simultaneously just two months after its release in July 2001.

10,000 Days achieved multi-platinum certification for the first time this month. It's previously stood at singularly platinum (and, again, simultaneously gold) since its 2006 release.

But a lot has changed since Tool last racked up the platinum awards. Before the advent of online music and streaming, RIAA certifications were more of a straight-ahead game. These days, with digital music being the primary kind purchased, the association's awards count album sales, song sales and on-demand audio and/or video song streams when totaling certification numbers. (It’s currently computed at the formula of 1,500 on-demand audio and/or video song streams equals ten track sales, and thereby one album sale.)

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