‘Jagged Little Pill’ has been re-released in a deluxe edition. (Photo by John Salisbury; courtesy Rhino)

It seems impossible to imagine that two decades have passed since Alanis Morissette made massive waves with one of the ‘90s most pivotal albums, “Jagged Little Pill.”

Potent and intensely emotional but also highly polished and commercial, “Jagged Little Pill” is one of the decade’s cultural landmarks. In celebration of the album’s 20th anniversary, Morissette has teamed with Rhino Records for a new four-CD Collector’s Edition. It includes a newly remastered version of the original album, a disc of demos and outtakes of songs that did not make the record, an entirely acoustic version of the album (which Morissette had previously released in 2005 to mark its 10th anniversary), and a CD capturing Morissette’s first live performance in the U.K. at the Subterranea in London in September 1995, just as “Jagged Little Pill” was really taking off.

Is it worth it to pay the $40 or so to pick up the collector’s edition if you already have your original CD from 1995? For most casual fans, the answer is going to be no. Yeah it’s a nice enough set and the packaging is lovely, but the most essential part of it is the album itself. While the remaster sounds nice, it’s not such a revelation that the original CD pressing should be considered obsolete. Of course, it is indeed a classic album. Morissette took to her blog recently to reflect on “Jagged Little Pill,” and she describes its meteoric impact as only she can: “There was a cultural wave swelling … a readiness, perhaps, for people to hear about the underbelly, the true experience of being a young, sensitive, and brave person in a patriarchal world… This wave was moving through culture with or without me, and I happened to grab my glittery surfboard and rode that wave like a feisty androgyne on the back of a megalodon.”

The first big hit was “You Oughta Know,” an obsessive, confrontational, angst-ridden rocker that took alternative radio by storm and then crossed over to MTV and the Top 40. It remains one of the decade’s most iconic singles, an anthem for those not content to fade away meekly after being wronged. “Right Through You” exists in the same stylistic territory, and the trippy rocker “All I Really Want” opens the album with a bang. Most of “Jagged Little Pill”, though, is engaging, well-polished pop/rock. Singles like “Ironic,” “Hand in My Pocket,” “You Learn” and “Head Over Heels” all became substantial hits, leading “Jagged Little Pill” to 13 weeks at no. 1 on the U.S. album chart and to worldwide sales in excess of 30 million copies. The album holds up very well two decades later, and it’s an enjoyable blast from the past to listen to these great songs again at full volume.

Unfortunately the three discs of bonus material are largely inessential. The collection of demos is at least somewhat interesting, but it’s clear from the beginning there is a reason why these songs did not make the album. Tracks like “Superstar Wonderful Weirdos” and “Death of Cinderella” are really just unfinished sketches, although some of them sound like they might have been quite good had they been fully fleshed out. In their current state, unfortunately, they aren’t compelling enough to inspire repeated listens.

The acoustic disc — which many fans probably already own — is rather sedate and bloodless. One of the things that makes the original “Jagged Little Pill” so great is the manic energy, and that’s missing here. Some songs work better than others. “Perfect” and “Mary Jane” are lovely, but the edgy rockers like “You Oughta Know” and “Right Through You” just sound limp. The live disc, again, will mostly appeal to hard core fans. Despite it’s status as a historic show — Morissette’s first performance in the U.K. — it doesn’t really jump out as the fierce live document that one might expect. The sound quality isn’t particularly great, and Morissette’s vocals are a bit rough at times.

Those who prefer the middle ground can get the two-CD deluxe edition which includes only the remastered main album and the CD of demos. That may be the way to go if you really feel the urge to upgrade your well-worn 20 year-old original. “Jagged Little Pill” is undoubtedly a cornerstone album that is worthy of exploration for a 20th anniversary edition. However, if you have the original CD, you can celebrate its anniversary just fine by revisiting it, preferably at as loud a volume as possible. The new 4-disc collection is a nice collector’s item for the die-hards, but casual fans will probably skip through the bonus material once and then never revisit it again, preferring instead to focus on the stellar original album, and understandably so.