Best approach for time warping

Cubase
#1

I have been struggling to get a previously recorded audio track to align with the project click tempo and am looking for any good tips. I’m using LE 5 and have been considering upgrading to 6 if it can solve this problem for me. The track I’m trying to warp is a slow ballad (I Can’t Make You Love Me) about 83 bars long without a lot of defined transients. I’m trying to create a backing track of this transposed up a step and want to use the original for reference.

The project is set to 60 BPM. When I import the track into the project and set Musical Mode it looses sync with the click in about 10 bars. I’ve tried slicing the entire track using manual and/or automatic hitpoints and then dragging the events to the correct beats. That works somewhat after I close the gaps but its pretty labor intensive. For my last effort I used Finale 2012 to tap in a tempo track and imported this into Cubase as a MIDI tempo track. This is similar to what Cubase 6 does automatically with its Tempo Detection algorithm. This actually worked pretty well (with Musical Mode turned off) although it fell out of sync with the click after about 40-50 bars. I could tweak the tempo map manually and try to get the remainder to fit over the entire track but this is also pretty labor intensive.

Has anyone found an audio warp or time stretch procedure or algorithm in any version of Cubase that just works for freely recorded audio tracks without a lot of hassle? The demos on YouTube for Cubase 6 Tempo Detection seem to fit the track perfectly but I’m skeptical that this is really that easy.

#2

Try importing the file into a project set to the original Tempo, go to the pool and make sure the correct tempo is noted there and the track follows the click, then select musical mode and change the project tempo to the new tempo. Does that then work?

#3

I’ve gone through the approach you’ve described a few times with limited success. The click drifts after 10 or so bars in all cases. I suspect this might be because the track is very legato with just a brush transient on 2 and 4. Whatever the algorithm is looking for gets confused as it tries to find the beat.
On the positive side I did find a technique that works and allows me to lock things correctly. My epiphany came when I realized it is easier to adjust the click to the audio track than to try to find the beat in the audio and have Cubase quantize it within the bar which is a much harder problem.
What I do is load the audio track into Finale and tap in a tempo track. Cubase LE 5 doesn’t have a tempo tap capability but Cubase 6 does. I export just the tempo track to a mid file and import it into a new project in Cubase. If you try to import it into an existing project it apparently doesn’t replace the project tempo track so you need to set this up before loading the audio track from the pool. Once the audio is loaded I go to the Tempo Track Editor and play back with the click on. I can go bar by bar and adjust any outliers to the tempo track that don’t fit the beats. Once this is cleaned up the click stays aligned and any VST tracks quantize correctly with the beats in the music. As I mentioned this is a labor intensive process but gives you maximum control.
In reading the documentation I think this is what the Tempo Detection algorithm does in Cubase 6 but as an automated process. This isn’t quite legit since the tempo now varies with the audio track rather than being locked to a fixed value but its close enough to allow using drum patterns and other replicated MIDI parts that fit with the reference audio track. This wouldn’t work if I was importing multiple audio tracks recorded at different BPMs but I’ll deal with that problem later.

#4

I didn’t realise the original file wasn’t conforming to a ridged click.