Will re-uploading songs update existing song records in Google Play?

Question

I suffered the same problem as Force Google Music Player to refresh album art? but I fixed it manually. That is, downloaded a local copy of the music on my phone and manually updated each MP3's album art. However, the web copy is still bad.

If I "upload" the fixed mp3 files will it update the files rather than upload a duplicate of it?

I don't want to try and have the latter happen and have a huge mess to clean up.

Answer 1

ChrisF's answer is mostly correct, but I think it has a subtle error:

If you change the name of the file Google Music will upload a new copy of the file as, as far as Google is concerned, it's a new file.

I don't think this is entirely true. When the Music Manager scans a file, it generates a hash of it (you can find this in the Music Manager local database - it's called the "client id"). Importantly, the hash attempts to depend only on the track's audio, not on filename or metadata tags (further details here).

This means that if you change the tags or filename, the Music Manager should recognize it as a change to an existing file and not create a duplicate.

That said, there are two wrinkles to their solution:

• the Music Manager doesn't recognize some ways of storing album art (eg if art is stored in a local file, but not in the file tags)
• the hash isn't entirely dependent on the audio, since tag stripping is done on a best-effort basis. You can see this effect by adding more obscure tags (eg adding an APE tag on the end of the file will result in a different hash, while an id3 tag won't).

Answer 2

If you modify the music file - retagging, changing the album art, etc, Google Music will update the existing file.

I thought that if you changed the name of the file Google Music will upload a new copy of the file as, as far as Google is concerned, it's a new file. However, that appears not to be the case and the identity of the file is derived from it's contents.

If you are worried about creating duplicates you could always download the file, delete it from Google Play - which doesn't delete the local copy - then update it. This "new" file will then get uploaded.

You can also update the file in Google Play itself without downloading the file. Simply click on the arrow in the bottom right corner (1) and select the "Edit Album Info" option (2):

Then click on the album art itself to change it: