Re: Showing differences between two versions of a score

This is interesting but not quite what I need. I’m interested in comparing musical differences, not visual changes.

I’d like something such as the pseudo code:

for(i, i < scoreA.bars.length, i++) {
   if (scoreA.bars[i] !== scoreB.bars[i]) {
      // bars are different, contrast the differences
   } else {
      // bars are identical, render normally
   }
}

On Thu, Aug 13, 2026, at 2:17 PM, Fr. Samuel Springuel wrote:
> The Gregorio project uses ImageMagik to visually compare scores as part of our test suite.  In our case we’re looking primarily to prevent small, unintended changes to scores unrelated to the change under consideration, but it catches larger changes too.
> 
> The issue is that it is entirely visual.  If you look at the attached image, you can see the kind of changes we’re looking at.  If you’re looking for musically important differences, this may be too sensitive for your needs.  If you’re interested though, I’ll post the series of ImageMagik commands that it takes to generate the attached (the process is automated for us, so I’ll have to dig them out of our test harness, which I don’t have the time to do right now).
> 
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> Fr. Samuel, OSB
> (R. Padraic Springuel)
> St. Anselm’s Abbey
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> 
> > On Aug 13, 2026, at 10:58 AM, Ky Decker <[email protected]> wrote:
> > 
> > I have two piano scores of identical length which have some harmonic and rhythmic differences. I’d like to write each piece as a separate .ly file and then programmatically combine them to highlight differences between version A and version B.
> > 
> > I’m imagining either:
> >     • Combining / “merging” shared notes, and then highlighting (in a different color) notes where the scores diverge.
> >     • Displaying smaller, secondary staves (treble, bass, or both) for measures which are not identical.
> > Is there a clean way to achieve this? Are there any existing examples of this sort of score comparison?
> 
>