This is an important release, well deserving of its four-star rating. This 2CD set is by what has become known as ‘The Great Quintet’ of Miles Davis. The significance of these recordings is that for the first time ever, the complete session reels for the entirety of the album Miles Smiles have been released, along with material that eventually found its way onto Sorcerer, Nefertiti, Miles in the Sky and Water Babies. Thus we can retrace the creation of Miles Smiles and the other material minute-by-minute, take-by-take with fumbled passages, rehearsals, random remarks and witty asides all available for public scrutiny. What's more, transcriptions of the studio dialogue for all songs on this set are available at www.plosin.com/milesAhead/Disco.aspx?id=BootlegFJD. It's an album set that uniquely concentrates not on ends but the means by which they were achieved. At the time, the quintet were moving away from Davis's established core repertoire that had held good since John Coltrane's stint back in the mid-1950s to a new library that favoured the time, no changes approach to improvisation. This had culminated in breaking apart Davis's old repertoire with this free-bop approach to improvisation – breaking open the established changes and forms and inserting interludes using the Ornette Coleman approach to improvising on albums like The Shape of Jazz To Come, where time is maintained but the changes of the song and its form are not – in this case the acute ears of Charlie Haden shadowing Coleman in whatever direction his improvisation took. For Davis's group this had culminated in Live at the Pugged Nickel from 1965. Now they were looking for new material where traditional improvising (following harmony and form) could be mixed with time, no changes methods, and in some cases the theme is used to establish tempo and key and improvisation follows time, no changes principals. These are recordings that were extremely influential in changing the approach towards improvisation in the contemporary jazz mainstream, i.e. jazz away from the New Thing and Energy improvisers of the period. Except for the final four tracks on CD2, we have a complete session reel for every track and its culmination in a master take. Davis appears as an equal, joining in with the banter, offering ideas how each piece might be approached, sometimes having them rejected – “Naw, let's try this” – but eventually emerging as slightly more equal than the rest as he pulls each track together once options have been exhausted. This is a set about process rather than the end product and so there is a caveat – hence the reason for not awarding a five-star rating. Listening to the ‘process’ as a thing-in-itself can take, in the case of ‘Freedom Jazz Dance’ (virtually an exercise in fourths), some 23 minutes to achieve the master-take that follows, or almost 20 minutes in the case of ‘Fall’. However, once you leave the historical after-the-fact documentation aside, the false starts, the rehearsals, the fluffed notes, the banter and the noodling can cumulatively become a bit tedious. It's rather like a conjuror taking you into his confidence and telling you how he saws the lady in half. It rather spoils the fun – so listeners will have to decide between the importance of being an aural witness to the creative process, however tortuous it may sometimes appear, or leaving that for music students, historians, the academics and degree and doctoral dissertations in order to retain something of the original sense of wonder when listening to these songs for the first time, when you didn't know how the lady was sawn in half.