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- What is time stretching or expanding?
- Understanding how time stretching fits into the remixing process
- Working in Pro Tools, Logic Pro, Ableton Live, or Reason
- Calculating the tempo of the original track
- Dealing with wet vocal stems
- Importing vocals with the 10% time-stretch rule
- Comparing time-stretched vocals at faster tempos
- Putting a time-stretched vocal in context
- Setting up a session for double-timing a vocal
- Creating a 4/4 remix from a song originally in 3/4 or 6/8
- Tightening up a vocal that drifts from the click track
Skill Level Intermediate
Now it's time to calculate the BPM of the original track. Let's import the original version of the song which is called Breakdown Mode by Iyeoka. I open up the Audio bin by using the B key and underneath the Audio File pulldown menu I select Iyeoka > Breakdown Mode. It's the original MP3. Add it to the Audio Bin, click Done, and Logic will convert the MP3 to an AIFF. As you can see, and it's creating a waveform overview.
Drag the original out onto the Arrange window, close the Audio Bin, mute out my kick drum and contract the screen a little bit. I'll select the track that has the original mix on it, a Breakdown Mode and in my Plug-In menu select BPM Counter. So Logic's BPM Counter will now calculate the BPM of the original. And just to take a closer look at the waveform I'll increase my waveform view. So let's take a listen to the original version of Breakdown Mode and watch Logic's BPM Counter do its thing.
(music playing) Immediately, it went to 1:48 BMP, and then it shifted to 147.9. So in my mind I think we can trust that It's actually at 140 beats per minute. And one way to test that is to close the BPM Counter, and we will go to the beginning of our wave file here, trim up the space that's at the beginning.
Zoom in even closer to make sure we're actually at 0 samples right where the waveform begins and then slide our wave file over to measure 1. Again, always zoom in to make sure that everything is accurate. I'll shrink the screen, turn this down a little bit, and I'll actually bypass the BPM Counter for the moment.
I do that by holding of the Option key and clicking on the plug-Ii. Unmute me my kick drum pattern and just bring the level of the original track down a little bit so that I can hear the kick drum as well. Let's take a listen. But first we need to change the BPM in our Logic section. So I type in 148, and now let's take a listen make sure that everything is indeed tight against the grid at 148 beats per minute. (music playing) Sounds extremely tight to me.
One way to ensure that the audio hasn't drifted is to scan further into the song maybe 2 & 1/2 minutes or so and take a listen and see if everything is still tight. (music playing) And indeed it is. So 148 is the exact BPM of the song. It's so important to make sure that the BPM Calculations whether they're done manually or by the computer are accurate. I've had situations in the past where a track's BPM is 128.10, not 128.00, and I thought it was 128 which caused my vocals to drift slightly every few measures, and it wasn't until I went back and placed the downbeat of the original version right at the downbeat of measure 1 of my sequence, which we just did here, and then I scanned a minute into the song and realized that the BPM have been drifted.
So this is an extremely important part of the process. If you miscalculate the BPM of the original then you're not going to have the accurate Source BPM of your vocals when it comes to time stretching.