Yes, you can use iTunes Match on Lion. The one caveat is that if your sole purpose is to try and swap out all of your files for a better copy the chances are pretty good that at least some of your files won't match up, so the'll be uploaded instead. Everybody's mileage varies, but I haven't heard of too many people who got everything they owned to match.
This is the 16 million dollar question - none of us really knows yet. All we do know is that the matchng process is not 100% accurate right now, even if every match you are attempting are from CD rips. i've gotten ~85% success rate myself, so far - but YMMV.
From my own experience, there seems to be at least three reasons for this:
1. The album / song is not in their database. Self-explanatory and of course it's unfixable unless the album is added. There could be numerous reasons why the album/song isn't there - OOP, licensing issues, etc.
2. The waveform analysis they are doing is inaccurate. This is something Apple can definitely work on with future updates. Some people, myself included, have gotten around this by re-encoding the track to AAC or AIFF before a re-match attempt, but it doesn't always work.
3. Mastering differences. I'm fairly convinced that this is a factor as well. For example, the Beatles have at least two US releases, on CD -- on in the 1980's and the other in 2009. From my own testng, the 2009 remasters seem to match well with the iTunes database, but the 1980's CD's have issues. And the mono box is another issue since the mono versions aren't in their database at all but will sometimes get matched (which you actually don't want, in this case).
So the bottom line is that although I believe their matching process will likely improve over time, it will be unlikley that it will ever get close to 100% given the reasons I stated above.
As for whether or not you need to manually re-try, I don't know the answer. My guess is that once the track is in "uploaded" status, Apple will likely leave it that way until the user manually re-tries. But that's just a guess.
1. Right. I wonder if in the future it'll be possible to use US credentials to check the US store, and UK credentials to check the UK one — to try to get the most out of it.
2. Do they analyze the whole song, or just a 10s sample? Very hard for it to determine clearn/explicit versions, and remixes if it's just a short sample. But what if you re-encode the track, and then it doesn't match — you end up with a track that has likely been re-encoded 2-3x already (losing quality).
3. It'd be nice to change all the mono versions to the nice remastered ones though I have a lot of old Beatle's CDs and even vinyl rips (my friend had a machine)... any licensing issues there? It should be fine, no? In the end, it's the same song, same artist.......?
I agree with all you've said. I think to the question of whether one can "force a reassessment" the answer is yes, you can, but from my experience, you need to go through a fairly involved process to get uploaded files off the cloud before you can get the matching process to take a fresh look at your cleaned up copy. I haven't found a way around the fact since the cloud is synced to my library, I have to delete copies from the library too. So I'm having to play games with duplicates in order to get them off Apple's servers. Have you figured out a way to streamline this, or has perhaps Apple actually given us something in the recent update? I haven't tried to re-match anything since it came out.
I wouldn't want to make duplicates because I often go by "Date Added" metatags and it'd mess those up...
I think I'm just going to wait until all you early-adopters fix all the bugs, and sign up for iTunes Match when I can get 99% matching.
I think Apple should include the meta tags... not wholly, but at least partially — first make sure from the waveform, and then double-check with the meta tags... perhaps to know if it's an album version, compilation version, remix, or what...
Sure, then people could abuse it by getting a remix of a song by only having the original — but come on... what loss is that? What's the different if Pitbull says "dale!" a few times?
I actually have a lot of needledrops and they actually get matched a large percentage of the time (which I actually don't want - I prefer my needledrops to their versions). And some people actually bought the Beatles Mono boxed set because they preferred the mono tracks. So there are definitely two different camps, here.
I do know that they take song length until consideration because in at least one case I had an upload and then tweaked the song length in Audacity by adding a few seconds of silence, re-trying and then I got a match. There was someone else here that suggested doing that so it actually wasn't my idea. But again it doesn't always work.
As for the US/UK store, I've already found that CD imports I have generally match just as accurately as US CD's I have - even if the tracks are not visible in the US database. My guess is that the matching process uses their entire databse right now, and not just what's visible in one region. There are even reports that AC/DC tracks are matching, even though they aren't available to purchase in any region. I actually expect that to be "fixed" at some point in the future so I'm puposely trying to match tracks that I believe are imports first, before that functionality disappears.
I have a very kludgey way of keeping my non-matched tracks separate - I just copy them their own folder outside of the iTunes library and that way I just drag them into the database every week or two to re-try them.
You have to keep in mind that I don't use iTunes as my main library, so this works for me - I just use it for the actual matching process - it's also the reason why I can do my matching piecemeal as I just do a few albums at a time.
I've not heard of anyone who knows absolutely what the Match process entails, only that many people find songs that Apple doesn't match aren't any problem for other services and we all hope it's going to get better soon. For instance, I use Tuneup to straighten out some metadata. Its scanning process involves working with Gracenote and very few of my songs don't get properly matched that way. Songs I have right now match in Tuneup, are available for sale in iTunes, yet don't match, despite the fact that other songs on the same album do match.
I do a fair amount of vinyl ripping, for what that's worth and some of it does match, though the percentage generally isn't as good as matching stuff I pulled from CD. As for the legal aspects, you're asking if getting a remastered copy instead of one that's really what you have is a problem? Well, most would want a proper match and that wouldn't be one, but if for some reason what you have matches to a different version and you're happy with it, I'd think any legal issues would be on their end, not yours. Note that people are having a lot of trouble with explicit lyric versions being improperly matched to clean versions and they're clearly not happy with that, so it cuts both ways. I've heard the same gripe about longer versions getting matched with shorter versions too.
I am convinced that they either do not use metatags at all right now, or if they do it's not used as a major factor for matching - I've actually matched dozens of tracks as a test that had no tags at all.
But I understand why they wouldn't want to use tags - if they did, someone with a lot of time on their hands could just create MP3's with the same song length and tag them as a certain song, and it would match. Even if the file was a completely different artist. Waveform analysis is probably required just to allow iTunes Match to get past the RIAA.
Re¶1: I guess just like with explicit/clean and mono/remasterd, there should be some sort of one-by-one setting, or perhaps a global choice. I always prefer explicit and remastered, for example.
Re¶2: But song length is so arbirtrary! -/+ 10 seconds just because of when and how you ripped it, and from what — sometimes compilation albums add/take seconds of the original, and then ripping adds/takes.
Re¶3: That's cool. So the UK store works for you? I thought they were refunding... and where did they get the ACDC from if it's not on iTunes Store?!!?
Overall, for "Pro" users of iTunes, it seems that iTunes Match is too much work... I already invested a lot to make sure metatags are 100% accurate, album art appears, and everything. It'd be nice to have some automated ways for advanced users on how to ues iTM.