Notes and Rests

The general syntax for representing notes is:

The corresponding representation for rests is:

Both notes and rests are instances of GUIDO events; in particular, rests are treated as special notes, which have a duration but neither accidentals nor an octave value. Octave and duration can be omitted; if so, they are inferred from preceeding notes (or rests) within the same sequence or chord or assumed to have standard values when required (such as for musical playback or notation).

Note names

There are different systems of note names:

  • diatonic: c d e f g a h/b
  • chromatic: c cis d dis e f fis g gis a ais h/b
  • solfege: do re me fa sol la si/ti


  • Arbitrarily mixing these systems is possible, but discouraged.
  • h and b denote the same pitch-class (b being used in the international system, h in the german system).
  • si and ti denote the same pitch-class (si being used in the french and italian, ti in the english solfege system).


Accidentals is an arbitrary sequence of the symbols # and & (for sharp and flat); in particular,

## is a double sharp, && a double flat.


  • Accidentals cannot be used with rests.
  • Accidentals are valid only for the note in the description of which the appear.
  • The usage of arbitrary sequences of accidentals without a reasonable interpretation in CMN (such as #&#) is discouraged.
  • Chromatic pitch-classes are assumed to be different from alterated diatonic ones, i.e., c# != cis.


Octave is an integer number indicating the octave of the note, where a1 is the 440Hz a. All octaves start with the pitch-class c, so c1 is the c just below a1.


  • The usage of octaves beyond the range of -3 +5 is discouraged.
  • If octave is omitted from a note description, it is assumed to be identical to the last octave specified before in the current sequence.
  • Octave should always be specified at the beginning of each sequence. If this is not done, but an octave is required in the context of an application, a standard value of +1 is to be assumed.


Duration is specified in one of the following forms: