I'm trying to read Kozakura Shōji's piece Gen'ō for shinobue and biwa. A free sample from his webpage is uploaded below. I play shinobue and have familiarity with the traditional notation, but I'm new to Western music scores.
The fact that the score has no time signature, bars or measures makes sense to me; Japanese flute music often has free time and long fermatas of a more or less intuitive duration. But then I don't know how to read the accidentals. At first I thought in a piece like this they would apply only to the single note rather than "to the end of the bar", but the use of naturals ♮ seems to preclude that interpretation (unless the naturals are there merely for clarity?). I thought maybe they would apply to the end of the legato passage (shinobue is played legato without tonguing, so one legato passage in a single exhalation would be a natural unit); but that also doesn't add up, since the naturals are also used right after a slur bar has ended. So maybe they'd apply permanently until cancelled—but there's a passage with a E-D# E-E-D# E-D#-E-D where all the 'D#' in my transcription were noted with an accidental, so that doesn't make sense either.
Is there a common practice interpretations of what the composer must have meant with accidental marks in a measure-less score like this?
