Screen2.0

 
 
 

feature // 2008.03.14 08:50:40 [hh]

Und es geht doch: Polyphones Audio-Material wie in MIDI notenweise editieren

Der Münchner Audio-Spezialist Celemony hat sein aus "Melodyne" bekanntes Bearbeiten von monophonen Audio-Signalen jetzt auf polyphones Audio-Material erweitert - etwas, das bislang als unmöglich galt. "Direct Note Access" (DNA) erlaubt das Bearbeiten komplexer, mehrstimmiger Aufnahmen wie in einem MIDI-Editor. Dieses Announcement auf der "Musikmesse" in Frankfurt darf getrost als Sensation betrachtet werden, gilt die Idee in der Theorie doch als unmöglich. Screen2.0 bringt die Hintergründe.

Während der Pressekonferenz bearbeitete der Demonstrator eine mehrstimmige Jazz-Aufnahme und ließ live per Keyboard die Solo-Trompete in einer anderen Melodie erklingen. Gitarrenakkorde wurden in einzelne Töne zerlegt und ließen sich dann separat verändern, die von einem Streichquartett gespielten Melodien wurden nachträglich per Software verändert – ein durch die Komplexität des notwendigen polyphonen Erkennungsvorganges bislang unmöglicher Eingriff. "Aber was in der Theorie als unmöglich gilt, das kann immer noch in der Realität funktionieren", so Melodyne-Erfinder Peter Neubäcker.

Mehrstimmiges Audiomaterial wird so aufgefächert, dass Noten in Akkorden erkennbar und einzeln editierbar sind. Eine von mehreren Instrumenten gleichzeitig gespielte Note kann damit allerdings nicht isoliert werden. Der Zugriff von Melodyne auf Tonhöhe, Timing, Dauer und andere Parameter soll dadurch auch auf einzelne Noten erweitert werden.

Bislang konnten nur alle Noten in einem Audio-File um einen konstanten Betrag geshiftet werden. Jetzt können Timing, Tonhöhen und Lautstärke von Gitarren-Akkorden individuell und live bearbeitet werden. Das eröffnet völlig neue Produktionsmöglichkeiten, Produzenten können nachträglich "verspielte" Stellen korrigieren oder verstimmte Gitarren nachträglich "stimmen".

Natürlich können auf diese Weise Loops oder ganze Songs komfortabel "geändert" werden. Aus Songs werden neue Songs, Loops passen sich an Harmonien oder neue Melodien an - und as laut Hersteller ohne Einbußen in der Klangqualität. Das Material kann auch per MIDI-Keyboard live gespielt werden und sich entsprechend anpassen.

Das neue Verfahren soll in alle kommenden "Melodyne"-Produkte integriert werden, das erste Produkt wird "Meldodyne 2 Plugin" im Herbst 2008 sein. Die Vollversion des Plugins wird voraussichtlich 350 Euro kosten, ein Update von Version 1 mit 130 Euro zu Buche schlagen.


Fragen und Antwprten von den Machern

Q: Is it possible with Direct Note Access to change individual notes in existing multi-voice (polyphonic) audio recordings e.g. to turn a major chord into a minor?
A: Yes. That’s exactly what Direct Note Access makes possible. You can take a piano or guitar recording, for example, and change any note you wish – even if it forms part of a chord. Until now, such a possibility was just a pious hope, but our developers have made the impossible possible. And the sound is of the highest Melodyne quality!

Q: How should I visualize this intervention in the audio material?
A: The notes are displayed, as is customary with Melodyne, either as blobs in an editor or in conventional notation. The x-axis represents time; the y-axis represents pitch. Multi-voice (polyphonic) material, which was previously all displayed at a single pitch, is now split up into individual notes by Direct Note Access and these notes are then displayed spread out as separate blobs – each at its own pitch.

Q: What editing possibilities are available for the notes in polyphonic audio material?
A: With Direct Note Access, after detection, polyphonic audio material appears ‘exploded’ in the Melodyne editor in such a way as to let you see the individual notes of each chord at their actual pitches and edit them using the familiar Melodyne tools. As parameters, you therefore have access to the pitch, position in time and duration of each note as well as its vibrato, pitch drift and formant spectrum – you can also change the volume and even the internal evolution of each note.

Q: What applications does Direct Note Access have?
A: Just as with the editing of melodies, the possibilities range from subtle correction to creative refashioning. You can, for example, correct a wrong note within a piano recording, tidy up the timing of the individual notes of a chord and even retune an out-of-tune guitar after the recording has already taken place. You can also transform the entire harmony of a recording, transpose it in accordance with a given scale, or replace individual notes in a chord by others found in a different part of the recording or even played by a different instrument. The ability to change the formants as well as modify the internal evolution of notes yields additionally far-reaching FX possibilities.

Q: For what type of material is Direct Note Access suitable?
A: Direct Note Access is designed for single polyphonic tracks. You can use it for the quality targeted editing of a piano, a guitar or a string quartet. Optimum results are obtained with cleanly recorded signals to which as few effects have been added as possible.

Q: How about mixed signals i.e. where you have a piano and a guitar on the same track?
A: Direct Note Access recognizes notes in their harmonic and temporal contexts. It cannot detect which instrument has played which note. So if a piano and a guitar play the same note at the same time, you cannot edit the guitar separately. With Direct Note Access, you can access the note itself, which in this case means the signal of both instruments.

Q: Can I also edit entire songs with Direct Note Access?
A: You can load whatever you like and experiment. Doing so can be interesting and even fun. With complex signals or entire mixes, the note detection can however reach its limits and perhaps not all the notes will be identified correctly. Direct Note Access is designed for the editing of individual instrument tracks in the course of a typical multi-track music production. In this context, the sound quality of the results is outstanding.

Q: Is Direct Note Access also suitable for transcriptions and polyphonic Audio-to-MIDI?
A: Yes. Once the notes have been detected in this way, MIDI export of the audio file with a view to printing out the notes is naturally one option; outputting the MIDI data of a previously detected file in real time (audio-to-MIDI) is another.

Q: Do you have any videos demonstrating Direct Note Access?
A: Yes. See here for a 7 minute video presentation.

Q: When will Direct Note Access be available?
A: Direct Note Access will be available for the first time in Version 2 of Melodyne plugin, where the emphasis will be upon the correction of polyphonic signals. Melodyne plugin 2 is due for release in the fall of 2008. The full version will cost 349 Euro/399 US$. The update from Version 1 will cost 129 €/129 US$. Customers purchasing Melodyne plugin after the 12th March 2008 will receive the update free of charge.
Naturally Direct Note Access will also be available in the large multi-track versions of Melodyne i.e. Melodyne cre8 and Melodyne studio, where the musical possibilities will be far-reaching. However no concrete release date has yet been set.

Weitere Informationen: www.celemony.com/ cms/ index.php? id=dna

 

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