I thought about a "let ring" at the beginning of the score, but it seems a bit too vague. On the other hand, I probably need to give indications on what note should be played on what string to get the harp effect of overlapping second intervals. This alone clutters the score quite a bit already. Anyway, thanks for the response. I'll try out a few things. The piece in only a draft at the moment, so I don't really know what will work best for the finished score.