If you are looking for a 'Complete' Abba Collection, then "Thank You For the Music" is the set for you. From reading the book that came with the CD set, it appears that most of Abba's released material is on here. The released material is contained on 3 CDs and a 4th CD contains rare unreleased material.
It seems that nowadays everything that is above 2 CDs that is considered a "Boxed Set". There really have become 2 categories of Boxed Sets. The first is a "Classic Boxed Set". This comes in a covered box about the size of an LP and contains CDs (sometimes in jewel cases, sometimes just on the bottom of the box) and a book about the same size. The second type is more like a 5.5" x 10" hardcover book which I term "Hardcover Box Set'. The CDs basically are stored in the hardcover binding and the book is in the middle. I much prefer what I call the Classic Boxed Set to the Hardcover format. The ABBA set is a Hardcover format. This is disappointing to me because for a 'Complete' collection, I would have liked to see the better presentation. Each CD has an A or B on it and a corresponding pseudo autograph of one of the band members first name.
But don't let the presentation deter you. The content is in this set. What is nice is that the first 3 CDs contain the released material. All of the released material is in sequential order of the release dates. ABBA Gold which is a greatest hits CD did not do this. In the attached book, Carl Magnus Palm has an outstanding disocgraphy that tells when and where every song was recorded and a brief abstract containing some useful information on the song. The discography is also contains pictures of ABBA album covers and singles.
The real gem of this set is the 4th CD - this contains the rare and unreleased material. There are 2 medleys - "Pick a Bale of Cotton" and "Abba Undeleted". The Abba Undeleted medley is fantastic. It basically has raw unmastered recordings melded together - outstanding. There are also non English versions of Waterloo, Ring Ring, and Honey Honey.
The attached book is also a nice thing to have in your collection. There is a 'brief' foreward from Frida, Agnetha, Benny, and Bjorn to introduce the collection. Manager and lyric writer Stig Anderson also writes a brief preface. On the page with the Stig Anderson preface is a photo of the band in which Agnetha and Frida wear the kitty shirt/dresses from the SOS video. In general, I wish all of the photos were larger - especially that one. The whole booklet contains lots of pictures and photos that really embelish it nicely. There are then 3 articles by various writers the chronicle the history and impact of the band, a section on ABBA memorabilia (that includes a photo of the ABBA action figures), a section devoted to ABBA outfits (yes the kitty shirt/dresses are mentioned), the discography, and a section on credits to the box set.
There is something for everyone on this boxed set. It is good for the deep fan as well as good for the casual fan. Highly recommended.