Once you’ve had the biggest-selling album of all time, what do you do for an encore? That’s the unique question that Michael Jackson and producer Quincy Jones faced as they prepared the follow-up to the record-setting worldwide smash “Thriller.” And while “Bad,” released in August 1987, may not have initially been the behemoth retail phenomenon that its predecessor was, it was the album and accompanying world tour–there was no tour for “Thriller”–that certified Jackson as the biggest musical artist and pop icon of the 1980s.

And that’s exactly what it was designed to do. While “Thriller” was derided by some critics as having “filler,” every song on “Bad” was designed to be a hit. Sure enough, a stunning 10 of the 11 cuts on the album were released as singles. It was the first album ever to boast five consecutive No. 1 singles, a few of which are among the singer’s most infectious pop creations–put on “The Way You Make Me Feel” and see if you don’t start dancing in your chair. This is where Jackson’s every vocal tic and glottal stop, every “sham-on” and “hee-hee,” became part of the pop vernacular.

To celebrate the album’s silver anniversary, the Epic/Legacy label has released “BAD 25,” a deluxe box set featuring the remastered album, a second disc of unreleased demo versions and remixes and, most attractively, a complete 1988 concert recorded at London’s Wembley Stadium on both CD and DVD. The set also includes two thick, full-color booklets, complete with album credits, photographs and essays; the booklet accompanying the live set also recounts the entire itinerary for the 17-month “Bad” world tour. (The original LP and demo discs are also available in a separate two-CD set.)

There’s much to recommend here, particularly for those interested in witnessing Jackson’s creative process. Many of the demo tracks sound scarcely like demos–despite improvised or unfinished lyrics, songs like “I’m So Blue” and “Streetwalker” would have fit right in on the album. “Price of Fame” is a sly “Billie Jean” callback; “Al Capone” is an embryonic version of what would become “Smooth Criminal.” Also included are two foreign-language versions of “I Just Can’t Stop Loving You,” plus brand-new remixes of “Speed Demon” and “Bad” that add EDM and rap elements. (Needless to say, the remixes are the weakest part of the set.)

The real jewel here is the never-before-seen July 16, 1988, concert video. Restored from Jackson’s personal VHS archives, the set finds the singer at the height of his talents, performing for a crowd of 70,000–including Prince Charles and Princess Diana–and backed by a terrific band that includes lead guitarist Jennifer Batten and a young Sheryl Crow on backing vocals. It’s an electric performance, packed with solo hits and a few from his Jackson 5/Jacksons days.

Completists will require this set, but it’s also recommended for younger fans needing an example of what made Jackson such a one-of-a-kind performer.