The mysterious art of beat mapping in Logic

So, for my sins (and because I have one studio more that everyone else) I've been given the job of doing the early stage mixing of six new Caedmon tracks.

When we first started recording, we decided to work to a click track because it would make everything much simpler when it came to drop ins and edits and loops and the rest. By the time we came to the second recording session, we had binned the idea of click tracks and recorded everything 'live'.

Being the anal kind of guy who expects bar markers on the screen to line up with the bars we're playing, I decided to explore what's called 'beat mapping' once again. I'd wasted the best part of a day trying to do this on the 50th Anniversary Retreat and failed, but now I had the advantage of Google and Youtube on my side.

Here is the before and after, so you can see what I'm talking about:

And this is how to Beat your Map in Logic

So, without further ado, this is how to make your click track follow your performance instead of the other way around.

1. This is essential, and not always mentioned in other tutorials: lock your regions to SMTPE time code before you start. Otherwise, if your regions start at different positions or you have multiple regions per track, Logic will happily shift the regions to match the new bar positions you're going to create and your recording will fall apart. So select all regions, and using the contextual menu, choose 'Lock SMTPE position'.

   

2. Unless you've already fiddled with it, your current BPM is likely to be set to 120bpm. Use the BPM counter plugin on one track to give you some idea of the general tempo - preferably something simple like a kick. When you have a good idea of the average tempo, set it in the transport bar.

   

3. Beat mapping is a 'Global Track'. You'll probably need to expose it by modifying the Global Track configuration. So use the View menu in the arrange window to display your Beat mapping.

   

4. Now select the track that you're going to use to set the tempo and define the bars. Again, something like a kick track is ideal, but in this case I didn't have that luxury and used an acoustic guitar track (yes, I know the picture says 'Sam Bass'. OK, so the acoustic guitar got recorded on the track previously called Bass. I'll rename it - don't worry about it).

   With the track selected, click 'Analyse' in the beat mapping section. Logic will display lines to indicate what it calls the 'transients' on that track, below the bar and beat markers. Now all we have to do is line them up. Use the sensitivity box to increase or decrease the number of transients to suit.

   

5. Now comes the magic part. Using your pointer tool, click on a bar marker on the Beat mapping track, and drag down to the transient which matches that beat position. Advance along the track doing this once for every bar. Unless the timing really does drift dramatically, matching the first beat in every bar should be enough. Check your progress every so often by playing the track with the click switched on.
   

And that's it. Now you can work on your track secure in the knowledge that going to bar 36 will actually take you to bar 36. You can slap in Apple loops that will stay in time with your drifting tempo. You can happily cycle 4 bars while tweaking.

Credits

It would have taken ages to work this out without the beatmapping video tutorial on Youtube by SFLogicNinja and the advice in the Apple Logic forum.

(Below is an update to the original post, added in response to my own troubleshooting and Lionel Cartwright's comment below)

Increase the sensitivity

If you can't get the 'on the bar' beats all the time, try increasing the sensitivity and mapping one of the beats inside the bar. Maybe you can catch a snare on the 2 and 4? The tempo track doesn't have to change exactly on the first beat of each bar, as long as it keeps in time.

Use multiple tracks

If you have the luxury of a multi-track recording, try selecting one of the other tracks just for the difficult bit. The beat mapping doesn't have to rely on the transients from the same track all the way through.

Just don't click on the 'Detect' button, which will attempt to remap your whole tempo track for you, using the newly selected track.

Make your own tempo guide

Or just make your own! Create a new software instrument track. Load up a drum kit into the new track.

Now hit Caps Lock and your little virtual keyboard will pop up. Press '4' to select octave 1 and hit 'T' to get a closed hi-hat (A cowbell would be good as well). Now set the track to record and play 4 to the bar hi-hat through the difficult area - or all the way through if you want. If any of your recorded hits are a bit rough in timing, you can edit them manually until they groove along nicely. Just don't try quantizing!

Now, make sure that you've locked the SMTPE position on your new tempo guide track as before, and go back to the Beat Mapping panel. Check 'Protect Midi' to prevent the tempo track moving your notes, select your new tempo guide track, and see if you can't match up those last recalcitrant beats to your 4 to the bar hits.