On standard stuff, ACW seems to work pretty well, coming up with reasonable chords.

However, it seems to have a problem when the comping is pushed or laid back a little, coming up with the most absurd chords. If I manually move the bar start a little so that it lines up with the chord start, then the chord algorithm seems to perform much better. I've tried the tempo adjustments for slightly faster/slower tempos, but the problem is not tempo itself, but relative timing within the bar. I can't seem to find a way to shift all the tempo bars ahead or behind a small amount so the right chords are detected, other than manually moving each bar.

Several possibilities come to mind regarding possible future enhancements to ACW to mitigate this problem. First, it seem that each eighth-note position in the memasure is assigned a note the entire period, yet if I move the bar start just a fraction of the eighth-note, the correspnding notes change dramatically. It seems, then, that the "granularity" of the notes is much finer than it shows, so picking out the notes within a bar shouldn't be constrained to those shown. Second, such rhythmic comping makes new chords at a relatively higher volume than the decaying chords from the previous bar, so choosing the louder notes within each eighth-note might give a better chord choice.

If you could select say 16th note granularity, and if the note bars were colored according to their velocity/amplitute, then by allowing each 16th or eighth column of notes to generate the corresponding chord, the user could click the appropriate column depending on whether the comping was pushing or laying back. Having a way to shift the note columns in every mesure when selecting the 1/2 measure chord, and letting this "comping tempo" be a time-shift in the tempo map, the ACW could perform much better on rhythmic songs.

Anyone figured out a better way to do this without waiting for a new ACW?

Jerry Schneider

Not a feature I need often I usually can play along to most songs after the 3rd of 4th go, unless it's in 6 flats or sharps or more.

You did read the instructions/manual a few times right? And you are setting the first bar with a good degree of accuracy?

ACW does indeed get into a bit of trouble with certain genres of music, jazz being among them.

Not only for the "pushed" playing that is ahead of the beat, but also for the "behind the beat" style common among the better jazz players.

There is also another physical parameter worth mentioning here and that is the extensions on chords.

James Chandler Jr. once explained the situation to me during early Beta testing of the ACW.

The process is done using filtering algorithms, looking for the fundamental and then looking for frequencies at a certain amplitude that are stacked above that fundamental.

I've tried to put several paragraphs into that one sentence...

Anyway, there is more than just one factor or parameter at work here.

The timing is always important.

But there is also the consideration of the *audio quality* of the file in question.

As well as the chosen instrumentation and what kind of harmonics are involved.

One thing that is often overlooked by the jazzers and the ACW is the fact that if you are into jazz, you are also into developing your ears, or you should be, and able to get in there and correct those wrong chords that the ACW can come up with in a jazz tune.

The ACW can still represent a huge shortcut in the LAYOUT of a BiaB song, though. i find that it speeds up transcription considerably, no more counting bars for a listen, for instance, the format of the tune becomes readily apparent on the first pass of the ACW in most cases. That alone is a timesaver.


--Mac