The book Behind"Behind Bars: The Definitive Guide to Music NotationNotation", by Elaine Gould (Published Faber Music, 2011) states: "An accidental holds good for the duration of a bar. It applies only to the pitch at which it is written: each additional octave requires a further accidental." (p.78.)
An accidental holds good for the duration of a bar. It applies only to the pitch at which it is written: each additional octave requires a further accidental. (p.78.)