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IntroductionSignal Manipulation > Pitch and Spectral Envelope Modifications > Melodic Transposition
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Melodic Transposition

This treatment is not based on a BPF, but uses MIDI annotations to transcribe a melody. It applies to monophonic sounds and requires a prior F0 calculus.


Sonogram and F0 Analysis
  1. A sonogram analysis is not technically required, but it may be useful.

  2. Execute an F0 analysis. If no F0 analysis has been executed, the Melodic Transposition menu item is disactivated.

Quality of the F0 Analysis

If your F0 shows discontinuities, this might affect the quality of the transposition. You may add corrections in the F0 itself to improve the result.

MIDI Annotations

You can :

  • import existing MIDI annotations

  • create them in the sonogram window with the MIDI Annotation tool

  • choose Analysis/Generate Annotations from Fundamental. Automatic annotations will match the F0, but their pitch and duration can be modified.

The Sonogram Display will then show an Annotation and a Treatement option.

Check that the tuning actually matches the A4 440 Hz reference with the pitchfork, and possibly modify it in the Inspector.

Executing the Melodic Transposition


Select Treatment/Melodic Transposition.

Missing Annotations

If no annotations have been imported or created, AS will offer you to generated MIDI annotations automatically from the F0 , provided an F0 analysis has been done.

Press OK.

  • The melodic transposition is now represented by a Tranposition block in the Processing Sequencer and can be manipulated and edited just as any treatment.

  • The Inspector has the same Tranposition label as for a constant or dynamic transposition. The Melodic and Use Annotation options allow to distinguish this transposition mode from the other and cannot be modified.


Notes About MIDI Annotations

Using Annotations
Automatic annotations generated from the F0.
Automatic annotations generated from the F0.

To execute a transposition, annotations must be different from the fundamental. If several annotations overlap, the lowest pitch only is considered. Pitches and durations can be modified via the Inspector or Sonogram window. Other parameters, such as velocity and channel can also be modified but won't be of any use for a transposition. For detailed information, refer the corresponding section.

MIDI Annotations
Annotations from Markers

If markers were added in the sonogram, you will be offered you to generate the annotations using markers as boundaries.

Useful Displaying Options

Pitch Grid

To display the notes MIDI grid : chooseWindows/Show Grid Settings

  • Check the Frequency grid option.

  • If necessary, modify the value of the Middle A Frequency prompt.

  • You can possibly hide the piano roll with the Piano roll option. Note that this option is not active if the Frequency grid is not displayed.

Frequency Grid

To adapt the sonogram scale to the piano roll – or staff – scale, Ctrl click on the frequency axis of the window and choose a logarithmic scale.

Sonogram Scale
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