Find the first note in staff notation that you wish to translate into a letter. Take note of both the clef (treble, bass or one of the C clefs) and the instrument for which the music is written. If it is a transposing instrument (see Resources), you will have to transpose the written note to its concert pitch. For example, a C natural written for a B flat clarinet will actually sound as a B flat, a minor second below the written pitch.
Determine the note's octave. This, too, requires understanding of the instrument, as music is often notated in the easiest octave to read, rather than the actual octave played. For example, music for bass violin is written an octave higher than it sounds. Music for tenor singers should have a small “8” at the bottom of the treble clef to denote that the music is an octave lower than written, but often does not; the notes sound an octave lower than written regardless.
Translate the pitch information into Helmholtz or scientific notation. In scientific notation, Middle C (the C right below the treble clef) is C4; an octave lower is C3, an octave higher is C5, and so on. In Helmholtz notation, Middle C is c' or c(superscript i). An octave higher is c'' and so on. The three octaves below it, however, are (in order) c, C and CC or C(subscript i).