Les Essentielles

This edition consists of 30 études from Cyrille Rose's 32 Études and 40 Études, selected and edited by Yves Didier.

Foreword:
"La musique n'échappe pas au principe de complexité croissante, impliquant des domaines toujours plus variés.
Acquérir rapidement les notions fondamentales pour s' ouvrir efficacement à l'actualité reste pour le musicien une constante essentielle.
Rendant un hommage affectueux aux maîtres éternels, l'auteur souhaite les honorer et faire vivre une tradition qu'il adapte au présent avec le souci de ne pas rompre la chaîne du savoir.
Avec un équilibre entre technicité et expression musicale, il propose un cheminement concis dans la pratique instrumentale."

English: 
"If music becomes increasingly complex, it also becomes increasingly varied.
Musicians are constantly confronted with the need to develop basic fundamentals as rapidly as possible in order to cope with today 's music.
In paying homage to past masters, these little studies revive their tradition by adapting it to the present, without however breaking the chain of continuity.
A balance is struck between technique and musical expression, covering all the basic needs of instrumental performance."

Despite the cover page's indication that these studies are "for the first years," the editor's modifications do not significantly lower their difficulty compared to the original sources.  While Essentielles does slur together phrases which have more points of separation/inflection in the original Rose, in other areas, Essentielles calls for more demanding articulation skill, like the repeated independently-articulated sixteenths in etude No. 6's penultimate measure (where Rose slurs them).  Some passages are transposed up an octave, creating more high register demands compared to the original (ex: Essentielles No. 29's mm. 26-27 are transposed up an octave from the original)

The primary change is that Essentielles' studies are shorter, an average 30% shorter than their original counterparts.  Four of the studies have an identical length, and three more have only a few measures removed, but the majority have massive removals.  Often these come by way of removing repeated phrase fragments, which frequently changes an even number of bars in a phrase to an odd number, creating some non-traditional phrase balances.  This is perhaps most noticeable in Essentielles' No. 14, which becomes stilted and awkward as a result of the abridging.  

Progression comes only in the selection and organization of key signatures: the first 26 études stay within three sharps/three flats (17 of which have either one or zero sharps/flats).  The final four études include four sharps, five sharps, and five flats.  No key signatures are changed from the original études.

Readers are warned that a few chromatic scales are written using an unusual notation: only the first and last pitches are written, with a number in between indicating the total number of notes for executing the proper rhythm (ex: a "6" indicates a chromatic scale requiring six notes). In some cadenzas, the total number of notes isn't stated, and only the intermittent pitches are notated.

A list of the étude sources and outline of the changes can be viewed here.

CAMco offers a list of other Ferling/Rose adaptations and detailed edition comparison of the Rose 32 through The Rose Report.