If ever there was an intimidating box set, it is this one. Leo Feigin, founder and president of Leo Records, the great pioneer who brought Eastern Bloc jazz and new music wholesale to the west during the 1970s and 1980s, has issued perhaps his greatest achievement and worst defeat. This four-CD box set is a document of a historic jazz festival held in Zurich. Susanna Tanner of the Zurich Jazz Festival took advantage of the early years of glasnost and assembled a seven-day festival of Soviet jazz in Zurich in 1989. This is no mean feat considering Soviet bureaucracy, even under Mikhail Gorbachev. While her vision was realized on the stages of Zurich and well-documented in the European and jazz press, Swiss TV, and radio, no recorded document existed, though all of it had been taped. Enter Feigin, who had the unenviable task of putting some 20-plus hours of music onto four CDs and creating an adequate package for the box. What's more, in his and Tanner's view, a representative sampling of the musicians was not acceptable. Every musician who played at the festival had to be included on the set. If we add finally to this that most Soviet musicians of the time played very little free music, but actually structured with improvisation, this task became immeasurably more difficult. The fact that this collection exists at all is a minor miracle -- that Feigin was able to do such a skillful and tasteful editing job is an enormous achievement, to say the very least. In the liner notes he said he "had to become a butcher." What this really meant is that he had to become a ruthless yet aesthetically responsible editor. And he has succeeded in spades. Some of the most important performances here include those of Jazz Group Arkhangelsk, the Vyacheslav Ganelin (aka Slava Ganelin)/Mika Markovich duo, and of special interest, the Misha Alperin and Arkady Shilkloper duo, who released an album -- studio recorded -- of the music performed at the festival that sounded completely different than their performance. Feigin offers the performance uncut. Also represented here are the Leningrad duo of Vladimir Volkov and Vyacheslov Guyvoronsky, the Tarasov/Vapirov/Sayfoolin trio Slava Ganelin, Mika Markovich, Aziza Mustafa Fade, LosTri-O, the Vladimir Chekasin Quartet, Snow Children, Valentina Ponomareva, and the Anatoly Vapirov Big Band. The sound is stellar, the edit job precise and clean, and the energy of ther performances is as ecstatic as one would expect from such a historic occasion. There are no standouts here; virtually everything on these four discs is indispensable jazz and new music. Finally, the packaging itself is superb, with essays by Feigin and Alexander Kan in both English and German, making this set as necessary as a Miles Davis box set for fans of new music.