Before this goes too far, I should say it's Gabriel Prokofiev, grandson of Sergei. Gabriel is a British composer and electronic musician. This concerto, written for Branford Marsalis, premiered last year in Naples, Florida, and will be performed again this March with the Detroit Symphony. The concerto is for alto sax despite Branford's involvement, although he does seem to play exclusively alto and soprano as solo instruments in the classical setting. (Sometimes he plays orchestral parts on tenor sax.)
I suppose it's highly unlikely that anyone here has actually heard this work, but has anyone come across any thorough reviews of it?