Choosing the algorithm
- • The detection process
- • Melodic
- • Percussive
- • Polyphonic
- • Switching algorithms
- • Setting a default algorithm (Melodyne editor only)
In this tour, you will find out how you can select the algorithm used by Melodyne for the display and editing of notes.
The detection process
Any audio material you transfer to, or open in, Melodyne is subjected to an analysis designed to identify the notes of which it is constituted, so that Melodyne can make them available to you for editing. We call this process ‘detection’.
Notes can be detected and edited in monophonic (melodic) material, rhythmic/noise-based material and with Melodyne editor – thanks to its patented DNA Direct Note Access technology – even polyphonic material.
Please note that DNA is designed for tracks containing a single polyphonic instrument (a guitar, a piano, ...) and that it divides the material up according to pitch – not instrument. If two instruments play the same note at the same time, what is available for editing is a single note comprising the combined sound of both instruments.
In the course of the detection process, Melodyne itself takes a view as to what kind of material it is confronted with and decides which algorithm to use for the display and playback of the notes. The algorithm currently selected is indicated by a check mark or ‘tick’ in the Algorithm menu as well as by the blobs in the editing pane.
In Melodyne Plugin, a separate algorithm can be chosen for each transfer; in Melodyne Stand-Alone, for each audio file in the document being edited. Before you can change the algorithm applied to a particular transfer or audio file, you must first select one or more notes belonging exclusively to it. If you select notes belonging to more than one transfer or audio file, you will find when you try to change the algorithm that the requisite menu has been greyed out. In such cases, reduce your selection to notes belonging to a single transfer or audio file and it will be possible once again to switch algorithms.
Melodic material is monophonic, which means that only one note is ever sounding at any given instant. Please bear in mind, however, that reverberation can cause notes to overlap even in monophonic material, creating, in effect, a kind of polyphony. If melodic material is to be edited in Melodyne, therefore, you should aim for as clean and ‘dry’ (reverberation-free) a recording as possible.
The blobs representing notes in melodic material are displayed at different pitches. Whether the blobs are isolated or joined to other blobs depends on the way they were played or sung: staccato or legato.
This category includes not only recordings of drums and other percussion instruments but also noise and atmospheric effects as well as other material in which Melodyne cannot detect any clear pitch in the sounds. When the percussive algorithm is selected, successive drum strokes (for example) are distinguished, but they are all displayed at the same pitch. The blobs can still be raised or lowered in pitch, but the pitch ruler does not display the names of any notes but simply relative values in semitones. The scale functions are deactivated.
In Melodyne assistant and essential, polyphonic material is also assigned to the category ‘rhythmic/noise-based’ because neither of these editions is equipped with an algorithm for polyphonic material and such material cannot be displayed using the melodic algorithm.
Thanks to its DNA Direct Note Access technology, Melodyne editor is even capable of detecting, and allowing you to edit, notes played on polyphonic instruments such as the piano or guitar – including the individual notes that make up chords. When the polyphonic algorithm is used, the blobs are displayed in a similar manner to those of monophonic material, with the obvious difference that the blobs are stacked vertically (at their respective pitches) whenever a chord or harmonic interval sounds.
In Melodyne assistant and essential, the algorithm for polyphonic material is present but greyed out in the Algorithm menu. This is because in these editions you can still open and play back documents that were created by Melodyne editor and contain polyphonic material, and in such cases, Melodyne automatically selects the polyphonic algorithm. These editions do not, however, permit you to edit polyphonic material nor to select the polyphonic algorithm manually.
You can at any time select a different algorithm to that chosen automatically for you by Melodyne. You might want to do this, for example, if you find that the material has not been interpreted in a way that suits your editing needs. To do this, while playback is halted, select the algorithm you prefer from the Algorithm menu, whereupon Melodyne will reinterpret the material in the light of your choice and adjust the display accordingly. Note: when you do this, any editing you have already performed prior to switching algorithms will be lost. The right time to decide which algorithm you wish to use, therefore, is before you begin editing.
If in Melodyne editor you have selected the polyphonic algorithm manually but no pitches can be identified in the material, Melodyne will switch automatically to the percussive algorithm, since otherwise no notes at all would be available for editing.
Setting a default algorithm (Melodyne editor only)
In Melodyne editor, you can prevent Melodyne automatically selecting an algorithm during the detection process by setting a default, thereby stipulating in advance which algorithm you wish it to use. This can be useful if, for example, you regularly want to edit particular files using the percussive algorithm but Melodyne, each time they are opened, is interpreting the material as polyphonic. By preselecting the percussive algorithm in such cases you can save time, as you will no longer have to wait needlessly as Melodyne performs its polyphonic analysis, only to discard the results moments later when you manually select the percussive algorithm.
Do not forget, however, when you no longer need to impose your choice of algorithm on Melodyne, to check Automatic in the Algorithm > Set as Default sub-menu. Otherwise, since Melodyne remembers your default selection even when you quit the program, you might be surprised to discover when the program is next launched that your vocals have been interpreted as percussive ...