Creating a “Tempo Change” for Beat Buddy using Logic Pro X (LPX)
Purpose: BB lacks a tempo change capability. This tutorial shows how to create the an accurate effect of a tempo change using midi time stretching.
- This explanation presupposes a basic understanding of midi editing in LPX. There may or may not be similar tools available in Cubase, FL Studio, ProTools, etc. With regard to any other midi editing programs, including the built-in midi editor, I am ignorant and apathetic.
- This example uses an accurate time stretching feature, so after the point in the song in reached when the time is stretched, the beats will no longer line up with the BB visual metronome. You will need to use your ears, not your eyes.
- This technique creates a sudden tempo change, not a gradual change.
- With regard to 2 and 3 above, this will be most appropriate for OPB-type song files. The reason being that after creating these time stretched areas, it will be very unlikely that the resulting measures will end on the points designated by Logic as measure ends. However, it can be used to create a pseudo-ritardando, useful for an outro, as I will explain in a second tutorial, which will be posted immediately after this one.
Ok, you understand LPX, so let’s get started. First steps -
- Start with an OPB you’ve created that needs one or more tempo changes.
- Make note of the tempo change locations and the tempos needed.
- I am going to use a version of Wouldn’t it Be Nice that I just created from the midi file that Phil posted with his version. I chose this because Phil indicated it needed a tempo change to be true to the original. I essentially used his edited midi, just adding a little piece from the Accordion and Saxophone from the original into the piano track. The piano track was created from the Harp and the Steel String Acoustic guitar in the original. There is a hideous tremolo picking section in the original guitar part that Phil deleted. I concur.
- The original piece has a dead measure at the front which I cut. The original tempo changes were at 54 and 62, these are now at 53 and 61. The piece starts with a tempo of 118, and then goes to 124 after the harp solo. I am deeming this close enough to not be bothered with, and will treat it as 124. At measure 53, the tempo drops to 99. At measure 61, it resumes the 124.
- Apply a Split Regions to the OPB at 53 and at 61. I use the Command+T tool for accuracy.
Create a new track for this region, or if you have an existing open track, drag the region to it. Here, I have moved the region to a track left open after my merge of the tracks which created the OPB:
The magic will be performed by the midi transform tool. It is found under the functions menu for the tracks:
Select Functions>Midi Transform>Half Speed. Note that there is also a Double Speed option, but I prefer to use the Half Speed option for these types of manipulations, as I will explain below. When you select Half Speed, this window appears:
- Note several things about this window. In the lower half box, there are two drop down selections labeled MUL, and below them are value windows which each have 2.0000 entered in them. This is the command to be performed by the transformation. It will MULtiply the midi values by 2.0000, effectively making them a half speed section. The notes will be twice as long as they were originally. The Double Speed window uses a DIVide command, but I find it easier to think in terms of multiplying rather than dividing.
Even though this window is a preset for Half Speed in the Transform command, it does let you enter values, so you can make it any speed, not just Half Speed. To calculate the number you need to enter use this formula:
Original Speed / New Speed = Multiply Value
Applying this, we have 124/99 = 1.2525. 124 was the original speed. 99 was the speed for the slower section. (see 2 above)
- Before we can apply the transformation to the region, we need to give it enough room to hold the new longer region. Simply drag the right side of the region with the region end tool, not the loop tool, to give space. I usually make the region twice as long as it was originally, just to be safe. Before you do this, though, you’ll want to be sure that you will be able to find the accurate place to rejoin the regions. If you have a note in the region that goes all the way to the end of the region, you don’t nee to do anything extra. But, if you don’t, drag the last drum tick to the end of the region.
Then, lengthen the region:
Now apply the Midi Transform. Select the newly lengthened region, then select Functions>Midi Transform>Half Speed, and enter 1.2525 in both value boxes. Click Select and Operate. and you held see something like this:
Make sure Snap is Off, and then drag the right edge of the region to the end of the last note that you lengthened, or the end of the last note, if you didn’t have to lengthen one.