Logic Pro X changing date modified of audio files - Why?

Perhaps it's Schrödinger's cat Quantum mechanics problem, once you look at the files the date appears modified, if you hadn't looked at the files the dates wouldn't have changed.

That said, I'm thinking it's happening when the folder is accessed, and guessing it might be more of a function of MacOS.

In other words, I don't know either. But this does bump your question to the top.

You also might ask the question of the developers and ask for an email reply.

https://www.apple.com/feedback/logic-pro.html

Perhaps it's Schrödinger's cat Quantum mechanics problem, once you look at the files the date appears modified, if you hadn't looked at the files the dates wouldn't have changed.

HA! HA! This is not that far from the truth. Depending how you look at the file the "modified date" may be different.

I will not provide a complete answer. There are too many factors and I don't want to add to the anxiety to what really happens to the files when you open them... 😉.

The short answer: Don't trust the "modified date" and don't worry about it. It is only metadata and doesn't really indicate that the file was modified at that date. You can change the date with a simple command line command like "touch" for example.

Regarding tempo related metadata and earlier project versions: In most cases, no issues. It is all handled by APIs. BTW nothing prevents from removing all tempo metadata in the files.

WD

HaHa.. you got it WD!

It's interesting, just looked at a project created in an early version of Logic 9 on a PPC machine. I imported the project file and spent time changing external MIDI tracks into Logic software instrument tracks. Flex was never used, the audio files still retain their 2009 date stamp. A thumb drive was used to transfer the files last year, that didn't change the date either.

Logic 10.4.4 Sierra, perhaps it's related more recent versions of Logic/MacOS

Curious what versions the original poster is using.

There are so much inconsistencies with some file attributes (Metadata) handling among OSes, File Systems, applications and utilities over time that I just stopped worrying about them.

Ah! I see Edgar jumped in. Good! He explains what I implied. Just to add, nowadays most applications use work files: All the edit are done on a temp copy of the original file. Most of that is now handled by OS/File system APIs.

WD

Remember the term "nondestructive editing"? Nowadays we have to be a bit more specific what that means.

I don't know exactly what happeeds to your files, but here is something you might look into:

At least, starting with the Smart Tempo feature in Logic, there is a lot of stuff going on in the background. For example, analyzing files, creating metadata based on the analysis, and here is the drum roll, saving those (tempo related) metadata to audio files without telling you. I remember there were some discussions/conversations that raised a red flag when I heard that. Because that means that, although Logic doesn't alter the actual audio data (PCM code) of the audio file (and therefore being true to the non-destructive promise), it will change the audio file by adding metadata. Once that happens, the File System registered that as a modification of the file, and there you have it.

I find that disconcerting too and I don't like it because now you don't know if any modification happened "only" to the metadata or the actual audio data.

Two things that you can do a bout it:

Lock It

Lock the actual audio files on the Finder level. For that, use the Get Info Inspector instead of the Get Info Window. Select all files and use the opt+cmd+click action (the Inspector window shows how many files you have selected. Now, whatever you change in that window (i.e., Lock) will apply to all selected files.

Look at it

Another thing to investigate is to open the suspected audio file in a text editor like BBEdit. AIFF files have their metadata stored at the end of the PCM data. There you can see the Tempos, Markers, Original Recording start, etc in clear view.

Hope that helps,

Edgar Rothermich

Graphically Enhanced Manuals (GEM)

www.LogicProGEM.com