Online orders can be made here [site entirely in German].
I plan to give a more thorough review on this volume in the coming weeks, but for now all I can say is that the book, for me, is a dream come true. Here are a few "unboxing" photos, some samples of the content, and an excerpt from the preface to the edition.
The outside cover (the book production is strikingly similar to the 2009 Antiphonale Romanum):
And a look inside:
Here's the 'Ad te levavi' from page one (the graphic on the front cover is of this incipit–notice the melodic differences from the 1908 edition):
A page from the Kyriale, which appears to be identical to the previous editions:
And, lastly, a look at the Order of Mass, contained in the back of the book, which conforms identically to the usage in the 2002 Missale Romanum:
Again, a more thorough review of this volume will be forthcoming. For now, I will close with a few very informative paragraphs from the beginning of the five page preface contained in the new Graduale Novum:
UPDATE: This volume can also be purchased at a cheaper price here.PREFACE TO THE GRADUALE NOVUM
In its Constitution on the Sacred Liturgy, art. 117, the Second Vatican Council requested that a more critical edition (editio magis critica) be produced of the books of Gregorian chant, which had been published in the early 20th century on the basis of the reform of Pius X.
Convinced of the urgency of this request, a few members of the International Society for the Study of Gregorian Chant (AISCGre), founded in 1975, have been meeting since January of 1977 to begin work on restoring the chants of the Graduale Romanum (1908). They have been re-examining the ancient manuscripts that were consulted for the Editio Vaticana, in order to exploit the progress that scientific research has made since the publication of that edition. The aim of this group was to achieve a more accurate rendition of the ancient chants; the basis for their restitution work were the adiastematic manuscripts from the 10th century, which are the oldest witnesses of the melodies and are written without notation lines, as well as the most important diastematic manuscripts from the 11th century which do render the exact intervals of the melodies. With regard to the adiastematic manuscripts, the need for an editio magis critica already became apparent with the publication of the Graduel Neumé of Dom Eugéne Cardine (Solesmes 1966) and the Graduale Triplex (Solesmes 1979). The wide dissemination of these books had done more to strengthen the awareness of the importance of a revised edition than the scientific publications had been able to do.
After about two decades of common work, the scholarly results of this group of specialists, whose work is still in progress today, have been published, beginning in 1996 twice yearly as "Suggestions for the Restitution of Melodies of the Graduale Romanum" ("vorschläge zur Restitution von Melodien des Graduale Romanum") in the journal "Beit age zur Gregorianik" (BzG) by the ConBrio Publishing House (Regensburg). For each chant, not only were the suggested restitutions published for the first time, but also a detailed critical apparatus, which cited the pertinent manuscripts in support of each suggested change.
The appearance of the melodies will strike the casual reader as unfamiliar, not to say strange in the present edition in the case of a few chants. For example, alongside the familiar si-flat there is also a mi-flat, fa-sharp and do-sharp, tonalities that were "forbidden" in Medieval times by the theoreticians, but which were nevertheless sung in not a few cases, as is shown above all by the transpositions of Gregorian melodies that appear in many diastematic manuscripts. This fact has been known for over a century; but it has been comprehensively and meticulously confirmed above all through the researches of the last decades. Since the scribes who produced the adiastematic manuscripts did not render exact melodic intervals anyway, there had been no need for them to resort to melodic transposition in order to avoid "forbidden" tones.
May 34 years of collaborative effort bear its fruits through this edition and may it prove useful to the users of this book in the realms of scientific research and teaching, but above all in fostering a vibrant celebration of the Church's liturgy.