Steinberg Nuendo 3 Getting Started Manual

							14
Tutorial 7: Tempo matching
audio loops 
						

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About this tutorial
This tutorial aims to introduce one of the basic but perhaps most use-
ful Audio Warp features in Nuendo. Audio Warp is a generic term for 
a number of tools and functions that (amongst other things) allow you 
to tempo match audio loops to any given tempo using real time time 
stretch. 
In this chapter we will describe how to use the Audio Tempo Definition 
tool to calculate the tempo of the loops used in the project, and how 
to enter Musical Mode. Once this is set, the audio loops will follow any 
tempo changes in real time, just like MIDI events!
Loops, i.e. sampled musical phrases or beats of a specific length (a set 
number of bars at a specific tempo), have of course been around for a 
long time. 
Working with loops has several advantages; by establishing a basic 
set of building blocks, e.g. a drum beat, a bassline and some musical 
and/or vocal loops, you can get a song project underway very quickly, 
without involving time consuming programming. There are scores of 
sample CDs on the market, covering every possible instrument cate-
gory and musical genre.
With Nuendo’s Audio Warp features you can seamlessly integrate 
loops into your projects, matching any loops to the project tempo in 
real time! 
						

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Setting up
This tutorial is also based on an existing file, included on the Nuendo 
DVD. 
•Below, we assume that you have followed the previous tutorials and 
copied the “Tutorial Projects” folder to your hard drive.
If not, please see page 122. 
•Open the folder “Tutorial Projects” on your hard disk and double click 
on the file “Tutorial 7.npr”.
Whether file extensions are shown or not depends on the settings for your operating 
system.
The “Tutorial 7” project opens in Nuendo. The project is based on the 
same basic audio and MIDI files as used in the previous tutorials. The 
Project contains three audio tracks and two MIDI tracks connected to 
VST Instruments.
The audio tracks contain loops, either 1 or 2 bars long. The Drums 
track contains a 2 bar loop repeated 4 times, the “Wah guitar” loop on 
the Guitar track is 1 bar and repeated 6 times, and the events on the 
Strings track are 2 bars long and repeated twice. The tempo is set to 
75 bpm.  
						

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We will now increase the tempo gradually from 75 bpm to 90 bpm 
using a ramp curve in the Tempo Track editor. Proceed as follows:
1.Open the Tempo Track editor from the Project menu.
The tempo is currently set to 75 bpm which is shown on the vertical axis to the left.
2.Open the Insert curve pop-up on the toolbar and select “Ramp” as 
curve type.
3.Select the Pencil tool to the left on the toolbar.    
						

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4.Using the ruler and the tempo axis as guides, position the cursor at 
the horizontal position shown in the picture (the end of bar 8) and the 
vertical position of approximately 90 bpm, and click to add a point.
When you point in the Tempo Track display the tempo is shown in the box above the 
tempo axis in the top left corner.
The tempo will be gradually increased from 75 bpm to 90 bpm over the 8 bars.
5.When you are done, close the Tempo Track editor.
6.Start playback, and stop again when you have heard enough!  
						

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As you can hear, the audio and MIDI tracks drift out of sync almost im-
mediately. MIDI events are always adjusted automatically to the project 
tempo, whereas audio events have a fixed tempo and therefore remain 
unchanged. That means, that raising the tempo will cause adjacent au-
dio loop events to overlap, so that the end of the loop is cut.
In the Project window, this overlap is indicated by the darkened areas 
in the beginning of the audio events. As the tempo gradually increases 
the overlaps become greater.
In the following section we will make the loops follow the tempo 
changes just like MIDI tracks by activating Musical Mode!  
						

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Activating Musical Mode
In this particular case we happen to know that the loops in this song 
have a tempo of 75 bpm. However, you can use the basic method 
outlined in this section to match loops to any tempo even if you don’t 
know their tempo or if your loops have different tempos. 
The first step is to calculate the original tempo based on the loop 
length. Proceed as follows:
1.Double-click one of the “Slow Disco” events on the Drums track in the 
Project window.
•The Sample Editor opens. On the Sample Editor’s toolbar, you can find 
three numerical edit fields for setting time signature, audio tempo and 
bars & beats. For now, these fields are grayed out and cannot be edited.
If you do not see these fields in the Sample Editor toolbar, try adjusting the toolbar 
elements, as described on page 228.
2.Select the Audio Tempo Definition Tool (the button with a note symbol).
Note that there is a similar stand-alone button with a note symbol on the toolbar. This 
is used to activate Musical Mode which is described later.
3.Now the time signature, audio tempo and bars and beats edit fields 
become active and suggested values are displayed. The length (dis-
played in the infoline) and audio tempo values have been calculated 
automatically, based on the length of the loop compared to 120 bpm.
Here, the number of bars was calculated to 3 bars. But as we know 
the loop is in fact two bars long, we should change this:
4.Use the up/down arrows in the bars edit field to set the length to 2 bars.
The tempo is recalculated automatically to 75 bpm.    
						

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5.Click the Musical Mode button so that it lights up.
As the loop events on the Drums track refer to the same clip they are all adjusted to fit 
exactly 2 bars (as long as Musical Mode is activated) regardless of the tempo! 
Activate Musical Mode…
…to automatically adjust the “Slow Disco” audio events. When Musical Mode is acti-
vated for an audio loop, a note icon and two arrows are displayed in the audio event.
To the far right of the Sample Editor toolbar, there are a number of 
controls that govern the audio quality of the real time time stretching. 
There are several presets with self-explanatory names like Vocals, Mix 
etc., and an Advanced option where you can set various parameters 
(these are described in the Operation Manual).
6.Select the “Drums” warp setting preset for the Slow Disco loop.
7.Double-click one of the “Wah guitar” events, and repeat steps 2 to 6, 
but set the length to 1 bar and select the “Mix” warp setting preset.   
						

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8.Finally, repeat this procedure for one of the Hi Strings events, setting 
the length to 2 bars and selecting the “Mix” warp setting preset.
Now all audio events are in Musical Mode, and do not overlap anymore.
9.Activate playback.
The audio events now follow the tempo exactly, just like MIDI tracks! 
•The same procedure can be used for any loops as long as the inher-
ent tempo is stable. Simply enter the length of the loop and activate 
Musical Mode. 
Alternatively, you can adjust the audio tempo value, if you know the original tempo of 
your loop.
You can also tempo or groove match audio files with fluctuating tempo 
using Warp Tabs, quantize audio files and much more. The main Audio 
Warp features are described in the “Audio Warp realtime processing” 
chapter in the Operation Manual.  
						

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