Now that both BIAB and RealBand have awesome audio stretching capabilities that allow both for transposition and time stretching (while preserving pitch), I think a cool optional feature for ACW would be to do tempo normalization.

So after you go through and click F8 to determine all the bar lines, you generally end up with different tempos on each bar, but close to each other. It would be nice if ACW could normalize to the tempo to whatever you specify, adjusting the underlying audio to that normalized tempo, and resulting in an arrangement that now plays as if it were recorded to a click track.

So if bar 1 were 96 bpm, bar 2 were 97, bar 3 were 95, bar 4 were 96, I could normalize the tempo to 96. In which case everything between bar 2 and 3 were slowed down from 97 to 96 and everything between bar 3 and bar 4 were sped up from 95 to 96, all the while preserving the pitch of the underlying audio file. Bars 1 and 4 are already 96, so no changes are required there.

Then, when you exited ACW back to BIAB (or RealBand), you would have a song with a constant tempo of 96 throughout, and the underlying audio would be in sync. Seems to me it's just simple math, but I could be wrong.

I hope that made sense.

It's doable, John. Propellerhead Reason introduced that a version or so back. In fact, as of version 8, it does on the fly, automatically. "Start playing and pick your tempo later," is how they put it.

I figure it shouldn't be too difficult to incorporate. I would think it would make working with styles and RealTracks after getting the chord grid a lot easier than dealing with a tempo map of changes every bar. I would think that moving from BIAB to a different DAW would be easier, as well.

I do believe it should be optional, though.

It's optional in Reason, John. I didn't mean to suggest that it's active all the time.

You've raised some interesting questions here. Replies will depend somewhat on your use of the audio being processed through the ACW and how the audio was recorded. Will the audio be used in your production or are you just determining the chords, progression and tempo to create a backing track? How much drift in timing will be more of a determining factor than whether the recording is commercial or a track you played.

Each of these scenario's use a bit of different approach than the other. If the audio processed through the ACW will not be used in the final production, the actual tempo map is irrelevant to the final production all though it may be used throughout the various stages of production before finalizing your song or cover. The average tempo determined by the ACW is all you need. If the audio is a commercial production, it has likely used either a click track or quantization has been applied in a DAW at some point and the variations you mentioned can be tightened up in the ACW prior to exporting the tempo map into BB.

If this is a current project you are working on or something that's been a frustration in past projects, give a little more detail and I'll be glad to share my approach to getting things to match up.

This is in the realm of letting computers do what computers do best.

One example of where this is useful is that I have a number of recordings done by my former choir director where he sings in the left channel and the pianist plays in the right channel (he got one mike, she got the other).

We would like to make some arrangements made from these recordings using MIDI and/or RealTracks. Not really even looking for the chords in this case (since I already know them), but looking to line things up (which ACW does nicely in addition to chord recognition). These recordings were not done to a set tempo, but we would like the final result to be. And in the end, I would use his vocal performance in the final result, so it all needs to match. The tempo deviations aren't big, but it would be much easier to work with a consistent tempo. I can make this work using other means, but I would rather spend my time working on the arrangement than on readjusting individual bar lengths, which a computer should be able to do nicely on its own.

IMHO, that's a job for Reason. Here's why:

https://www.propellerheads.se/reason

The page is pretty deep, so keep drilling down on the tabs and headers.

Are you using Reason 8 or Reason 8 Essential??

Just curious.

DEeddy, I'm running Reason 6.5.2. I have the upgrade to 7 but haven't installed it yet, and couldn't afford 8. I'm on the Props mailing list, though, and try to stay current on features.

Richard

By the way, your avatar is intriguing. I just got a 2012 Country Gentleman.

Here is an experiment I just completed a few minutes ago and the results.

I have a solo rhythm guitar track that varies between 106 - 114 bpm according to ACW results. (I didn't record it -- Promise)

I imported the track into track 1 of RealBand. Executed ACW using the existing song and answered no to the keep existing bars question since I want ACW to develop the tempo map.

The ACW determined the chords, progression and tempo. The average tempo was 107.xxx I can't recall the exact number but it's not necessary since my intent is to use a whole number for the tempo. The chords were imported onto the chord chart.

My first attempt resulted in the chords not being in proper alignment so I ran the track through the ACW again and reset the first bar and imported the ACW results back into RB.

I selected the whole track and opened the time shift/pitch correct menu and ran it on the track setting the old tempo at 106 and the new tempo at 107.

Once that process completed, from the tempo map radio button I set the tempo at a fixed 107bpm.

Because of the variance in BPM's of the original track, I selected the entire track and made a minor alignment of the first chord with the first bar.

My track was now aligned at the fixed 107bpm. But the chords were now off by a bar because of the alignment. I had to re-enter the chord chart. However, near the end of the song, again, I believe due to such a large variance of bpm of the original track, the chords began to drift off from the proper bar alignment. It drifted about two measures of the four measure bar.

If I was planning to use this as John mentioned above with his choir director tracks, I would split the track and move the remaining measures back two beats and time stretch the last bar before the split so that any RB/BB generated RT's would be in time.

But looking for other solutions, in the EDIT/track menu was the option to align a track recorded 'free time' to a click track. I attempted this but the click track must be a 'C' note. I generated a generic click track in Audacity that RB could not read.

According to the help file, this advanced feature will likely accomplish what John would like to do with his choir director's recordings without jumping through all the hoops I jumped through.

I'll eventually try the alignment with click feature to see for myself.

The ACW is a sensational piece of software and gives reasonable results, but there is always room for improvement, and this would definitely be one.

+1

Great idea, must have !

I needed that in RB so many times but ended up doing it in Reaper, just do the ACW then
just write the metronome to a midi track, drag export midi track to Reaper then drag in the original audio.
Then I use Stretch Makers to Quantize the audio.
1. Set Project Tempo.
2. Grouped all tracks if more than 1 like drums.
3. Actions > Show Action List > New > Create an Action Hotkey to move to "Go forward one beat"
and "Item: Add stretch maker at current position" then Shortcuts for selected action > Add.
4. View > show Master Track.
5. Right click on Tempo points > select all
6. Right click on Tempo points > reset points to zero/center
7. Highlight track/s from start to end.
5. Item > Stretch markers > Snap Stretch Markers within time selection to grid.

Back to RB, remove the tempo map, just set the constant tempo and drag the Quantized audio rendered from Reaper into RB.

+1

I would like to add one thing to this suggestion and that is having an option to either create a constant tempo or create a MIDI tempo map based on the audio file.

I could use that tempo map in BiaB to create backing tracks, copy the MIDI tracks to my desktop, and have Sonar load the MIDI file. I would then have the correct tempo map for the pre-recorded audio file.

PS - If anyone knows of a program that will do this please let me know. Note that I find Sonar's process very complicated, I have had limited success using it.

+1

+1, if not but for the fact that we already got ACW and it works on our platforms. I'd rather see my current set of software improved than need to add more software.