Can I upload my own transcription of a blocked score?

[Yuezhou Lyu]

I bought some piano scores and full scores that are now blocked in IMSLP, for example, Prokofiev's 10 Pieces from Romeo and Juliet, Op.75. Now, I use one of the scores to write a transcription for accordion and going to upload it with the license of by-nc-sa. I am the arranger only want to share the score with other accordionists and do not want to publish it. Can I upload the transcription to IMSLP? Thank you.

[Rob Peters]

Depends on where you live. Since Prokofiev died in 1953, his work is still non-PD in countries that have the 70+ rule (like the EU). In countries with the 50+ rule (like Canada), his work is PD.

[steltz]

If the original piece is blocked on IMSLP, then your transcription would be blocked on IMSLP as well, unfortunately. It would be unblocked on the same date as the original piece gets unblocked.

I also need to caution, however, that you need to make sure that the edition you are working from is in the public domain in your country. For example, I notice that the editor on IMSLP's blocked edition is Atovmyan. Depending on the laws in your country, he may be entitled to some protection as well. If your edition has no other contributor other than Prokofiev, then his are the only dates you need to worry about. Otherwise, check the dates and the laws regarding editors in your country. A transcription made from a piece edited by someone under copyright is illegal.

[Carolus]

The editors of the Prokofiev complete works as issued by Muzgiz/Muzyka are "urtext" editors and treated accordingly. The nasty thing is the work's status in the USA which is tied up for some time to come.