iTunes Match "Criteria"?

[Tones2]

I've been looking at this some and it seems to be a combination of song length and price of song that throws off the matching. For albums that were only partially matched, when I look at the iTunes version vs my version, often times my version is a few seconds longer / shorter (due to the CD conversion process adding / subtracting seconds) or the iTunes song has a different price than the other songs on the album. (like $1.29 vs $.99 for the rest). The last song on a album is most likely for me not to be matched, probably because CD conversion may sometimes add length to the last song.

I'm not saying this is right or how to fix it, I just think that's what is going on. The only thing I'm sure of that's it's NOT taking into account the ALBUM NAME (since I change many of mine and I still get matches). I also do not think it's doing any type of audio fingerprint match as that would take WAY too long to do on large libraries - even a 5 second sample on my 13,000 song library would take about 18 hours not counting transmission time). So it looks like song name, artist, song length and PRICE (for some reason) are the important factors for match.



Tony

 

[aperry]

Interesting. I'm trying to figure this out as well. I was pretty happy to see that it matched 80% of my music, but then a little bummed to see several albums where all but one or two songs were matched.

In one album that I've decided to take a close look at, 10 of the 12 songs were matched. All of them are offered in the iTunes Store. Interestingly, the two songs that were not matched have lengths that are about 20 seconds different from the iTunes Store. The others are within 1 second of the iTunes Store length.

So I think you're on to something about the song length.

 

[imahawki]

I know you're not claiming absolute certainty with this theory but it doesn't match my observations. I have one album where only the FIRST track doesn't match. It is 1 second longer than the ITMS version but there are a few other songs on the same album that are off by 1 second (or more) that DID match. I hope Apple continues to improve this service. As it stands there is no way in HELL I would continue to subscribe. In fact with a nearly 25% failure rate, if it were more money involved I'd be pissed enough to try and seek a refund. But $25 isn't that much and I have some faith that some items that aren't currently matched will be matched at a later time due to Apple tweaking the match criteria.

 

[aperry]

It's definitely *only* the song length. I also have some songs that seem to be the exact same length and are not matched. But it seems very likely to me that length is one of the criteria.

Edit: Typo. It's definitely "not" only the song length. Sorry.

 

[mactmaster]

iTunes Match uses Gracenote MusicID. Here's an excerpt from the Gracenote website.

Digital File Identification:
MusicID can identify individual songs or albums in a user’s collection regardless of source, format, or tag information. Utilizing a multi-step process which combines [audio waveform fingerprint technology, (MusicID can identify music with short audio samples anywhere in the song)] with textual information analysis from the file’s embedded tags, file name, directory path, and other related files in the user’s collection, individual or groups of songs can be matched to albums.

 

[gloss]

iTunes Match uses Gracenote MusicID. Here's an excerpt from the Gracenote website.

They forget to note that it's apparently terrible.

 

[soco]

I guess the question now is, has anyone fooled Gracenote with pirated music?

I know iTunes Match picked up and matched my albums I ripped, but my Led Zeppelin discography was downloaded elsewhere as my father has the CDs and I'm not going to another state just to be politically correct. So I downloaded it and iTunes correctly uploaded it as it didn't properly match was was in the iTunes Music Store.