Copyright and the Prokofiev Flute Sonata Op.94...

[Florio]

I'm particularly interested in the copyright situation regarding Sergei Prokofiev's Sonata for Flute and Piano Op.94 (1943). Many of you will be familiar with this work, the flute part of which was later 'rearranged' for violin by the composer at the suggestion of David Oistrakh, the 'violin sonata' then being published as Op.94 bis.
Publication of the original flute sonata would appear to have a complicated history. The work was published by Muzgiz (Moscow) in 1966, and possibly also earlier. In 1946, Anglo-Soviet Music Press published a version that was distributed through Boosey & Hawkes; this hybrid edition reproduced the newly-composed violin part above the piano in the score, while the separate flute part incorporated many of the changes made by Prokofiev for the violin. Copyright was valid for the U.K., the Republic of Ireland, and the British Commonwealth (excluding Canada).
In 1958 Jean-Pierre Rampal prepared his own version of the work for the International Music Company ('international copyright secured'). This differed from the ASMP edition in that much of the articulation and phrasing (at least in the flute part) had been modified. Moreover, several 'alternative' passages were included in small type in the flute part; labelled 'original', these measures suggested a consultation of the original manuscript.
In 1960 Hans Sikorski issued an edition, which was revised in 1998. The 'Revised Edition' (as was probably also the 1960 edition) is copyright in Germany, Denmark, Greece, Iceland, Israel, the Netherlands, Portugal, Spain, Sweden, Switzerland and Turkey. It is purportedly faithful to the composer's autograph, even if the piano part contains 3 noticeable mistakes (missing or incorrect accidentals), some articulation would appear to be missing in the flute part (first movement), and the composer's original tempo indications for the first two movments ('Andantino' and 'Allegretto scherzando' respectively) have been ignored.
In addition to the above editions, several others are currently listed in catalogues, including those by Little Piper Music Publications, G. Schirmer, Megido Music Publishing and MCA Music.
This situation leads me to ask the following questions:
Firstly, how is it possible that there exist so many different editions of a work that is not Public Domain (Prokofiev died in 1953) except in Canada?
Secondly, what is the situation regarding copyright of this work in places like France, Austria, Italy (where I'm living) and Canada? Could, for example, the Sikorski edition be uploaded onto IMSLP and accessed by musicians in countries not subject to Sikorski copyright?
Thirdly, could someone legally prepare a critical edition or Urtext of the work, after consulting the autograph, and have it published, say in Canada, Italy, France or Austria (or better still upload it directly to IMSLP)?
Even if I'm here referring to only one work by a single composer, these considerations surely apply to other compositions by many composers.
Florio

[Carolus]

It's rather complicated, but the reason you can't download it here is due to the work's "restoration" to copyright status in the USA under the GATT/TRIPs amendments to the US law (Title 17). Before 1996, the Sonata, like nearly all of Prokofiev's works first issued in the USSR, was public domain in the USA due to Muzgiz's failure to comply with the notice and renewal requirements of the law in effect from 1909-1977 (which is why there were all those reprint editions). IMSLP, while hosted in Canada (where all Prokofiev first published before 1958 is free), is temporarily blocking items that are protected in the USA due to the huge amount of traffic emanating from there. This situation will hopefully change in the next couple of years.