Here’s another tutorial with fixed links for pictures:

Here’s a tutorial which can help you, along with part 2 of this tutorial, beatmap and acapella as perfectly as possible, by creating a special playback in purpose, that will be perfectly in time with the acapella.
For this we need the acapella of a song and the original song itself, as long as it’s the same edit/mix/version as in the acapella.

Here we took an example from a simple source for which tempo is almost constant, but of course it’s more useful when tempo varies because with such a simple source you only need to know the original tempo, apply it to the acapella and then find by ear (or sometimes visually) how it matches the best.

Let’s open the two files, acapella and original into Audition, multitrack mode:

During the introduction, you already which parts we need to layer and match. That’s why we’re going to move the acapella and stick it as tight as possible to the original.

Don’t hesitate to be as precise as you can be.

Now you need to make the limits of the original match with the acapella’s beginning and end, you need the basic selection tool (white arrow in the tool bar), the icon needs to appear as in the screen capture. The magnetic effect you can find in Audition allows you to fit the two borders together exactly no need to zoom.

In the end we see that the original is shorter than the acapella.

You really need our edit of the original to fit exactly with the limits of the acapella we want to use next. Double-click on the original in the multitrack mode to get into edition mode:

Go into Menu: Generate > Silence to add a few seconds in the end. Go back into multitrack mode, you’ll the original is longer.

Do the same operation we made before for the beginning of the track and match both clips’ ends together. When it’s done zoom out the whole project.

Double-click on the original to have it into Edition Mode.

Double-click on the present displayed selection, but don’t move into the actual view or zoom in/out.

Go into Menu Edition > Trim (Ctrl+T).

Then Menu File > Save as…

Pick MP3 as a format, or the format it proposes you, we don’t need a high definition sound.

Then open Live and create or open the project in which you want to use the acapella.

Beatmap the original (here, we have very few markers), without forgetting the warp marker right at the beginning. Then, drag ‘n’ drop the acapella on the clip frame. For various details and beatmapping issues coming from Live, just go see the previous part of this tutorial where small tips are given to you to handle everything which can happen to you.