Introduction

Frequency Grid Modes

Linear Mode

Definition

The Linear mode is the default scale of the frequency grid. It corresponds to the default frequency scale of the sonogram window.

The grid's steps are based on

  • equal intervals in Hz

  • a given offset (starting value) in Hz.

Interval and Offset

To modify the interval and offset of the grid, click on the corresponding prompt, enter a value and validate.

Harmonic Mode

Definition

The Harmonic mode is relative : pitch steps displaying is defined by :

  • an Interval in standard musical units and in cents,

  • a Base Frequency in Hz

Interval

To define the interval

  • click in the corresponding prompt, enter a value and validate

  • choose an interval in the pop up menu.

Both values are updated automatically.

The corresponding frequency value of the interval will evolve logarithmically with the base frequency. For instance, a minor second is always equal to 100 cents, but its corresponding frequency interval grows with the initial frequency value.

If an interval that doesn't belong to the standard musical scale is chosen, the following item will be displayed in the menu : choose interval .

Base Frequency

To define the base frequency, click in the corresponding prompt, enter a value and validate.

The grid will be updated, but this will of course not affect the linear value of the interval. Note that the grid cannot be calculated with a nil base frequency.

MIDI

Definition

The MIDI scale corresponds to the MIDI pitch standards. Musical intervals are represented linearly, which corresponds to a logarithmic display of frequencies in Hz.

MIDI Annotations
Pitches and Keys Display
Two cases. On the left, the zoom in frequency allows to display the notes names. In both cases, we have a logarithmic frequency scale.
Two cases. On the left, the zoom in frequency allows to display the notes names. In both cases, we have a logarithmic frequency scale.
  • The only variable parameter of the scale is the A4 reference value in Hz, which is defined in the Middle A Frequency prompt. To change this value, click in the prompt, enter a value and validate.

  • To get a linear spacing of the keys, choose a logarithmic scale in the Sonogram scale contextual menu, with a Ctrl click on the scale.

  • A minimum zoom in frequency is necessary to display the notes names.

Piano Roll Option

The Piano Roll option allows to display keys on the left of the sonogram. It is selected by default.

If the option is not selected, black keys will still be represented by pink stripes in the Sonogram window.

Grid and Sonogram Scales
  • Note that the Sonogram window scale – selected with Ctrl click on the frequency axis –can be more or less appropriate, depending on the grid type.

  • The Logarithmic scale is more appropriate to the harmonic, MIDI and staff frequency grids.

  • The Linear scale is more appropriate to the linear grid.

MIDI

Definition

The MIDI scale corresponds to the MIDI pitch standards. Musical intervals are represented linearly, which corresponds to a logarithmic display of frequencies in Hz. A piano roll, with pitches names and indices is set according to the MIDI steps of the grid.

Linear Keys Spacing

To get a linear spacing of the MIDI scale, choose one of the logarithmic scale in the Sonogram scale contextual menu, with a Ctrl click on the scale.

MIDI Annotations
Intervals Representation
  • The A4 reference value in Hz is defined in the Middle A Frequency prompt. To change this value, click in the prompt, enter a value and validate.

Staff Mode

Definition

The staff mode represents musical intervals on standard staves. It is quite similar to the MIDI mode. Additionnally, the number of additionnal staves below and above the basic tenor and bass staves can be set in the window.

  • In the Sonogram window, staves are represented with black lines.

  • In the Instantaneous Spectrum window, staves are represented with pink lines.

Staff

The staff mode represents musical intervals on standard staves. It is quite similar to the MIDI mode. Additionnally, the number of additionnal staves below and above the basic treble and bass staves can be set in the window.

  • To set the A4 reference value in Hz, click in the Middle A Frequency prompt, enter a value and validate.

  • The Piano Roll option is selected by default.

  • In the Sonogram window, staves are represented with black lines. Additionnal staves are represented with dotted lines.In the Instantaneous Spectrum window, staves are represented with pink lines.

Linear Staff Spacing

 To get a linear spacing of the staff lines, choose a logarithmic scale in the Sonogram scale contextual menu, with a Ctrl click on the scale.

Intervals Representation

To set the number of additionnal staves above and below the basic staves, click in the Extra Staves Above-Below prompt, enter a value and validate.

  • Additionnal staves are represented with dotted lines.

  • The maximum number of additionnal staves matches the usual musical fundamentals, and doesn't exceed a G8 or a F-1.

  • Frequency Grid Modes
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