It pays to poke around in your music folder from time to time to eliminate inconsistencies. Yesterday I had a look and found two folders for Jane's Addiction: "Jane's Addiction" and "Jane_s Addiction". I had a look in iTunes to confirm that there is one artist with that name.
Here's what I think happened. I ripped one CD with iTunes 4.1 and the other with 4.2. It seems that with 4.2, Apple changed the way the app names folders to make them more compatible with Windows. As far as I know, Windows is picky about certain characters in filenames, whereas Mac OS doesn't care unless it's a colon or slash. I've seen the use of the underscore in music folders on a PC in place of certain characters.
I didn't like there being two folders for the same artist in the music folder, so I selected all the songs from both albums and renamed the artist to "Janes Addiction". Then I renamed it again, this time with the apostrophe. When I looked in my music folder again, both albums had been combined into the artist folder "Jane_s Addiction".
I didn't want to risk confusing iTunes, so I didn't alter the folder structure directly.
I just found that you can rearrange the sequence of multiple album art. Click on a song, then get info. Click the Artwork tab. Click on an image to highlight it, then click and drag it to where you want it to appear in the sequence. Click Okay and go back to the library. You won't notice any difference until you click elsewhere, then click the song again (a bug, I presume).
I have found that classical music often comes with more than one composer's music on a disc. I have a disc with music from Ravel, Debussy and Mussorgsky.
The artist and composer tags are simple, but all of this disrelated music is held together by the ungainly album name of "Bolero/La Mer/Pictures at an Exhibition". I split the disc into 3 albums, each related only to the composer in question. This makes it a lot easier to organise and find.
I also split a disc with two sequences of music from the same composer, Elgar. I've now got 2 albums: "Enigma Variations" and "Pomp and Circumstance Marches". I've also set the Grouping tag, but I still like them separate.
Did you know that you can have multiple pictures assigned to a song's artwork tag?
Why would you do this? Example: Jane's Addiction "Strays". The limited edition of this album that I got came in a slipcase. The slipcase is therefore the front cover of this particular CD. I scanned this and tagged it as my artwork. I then scanned the CD booklet, which is also the cover of the standard edition, and added that as well. Now I can see both the limited and standard edition artwork.
To do this is simple. Firstly, select all the tracks to which you want to assign a piece of artwork. Drag the artwork to the lower-left artwork pane of iTunes (you may have to show it using Edit/Show Artwork or Apple-G). Then drag the second or subsequent artwork onto the artwork pane. iTunes will add each new artwork to the songs. You can scroll through them by clicking the arrow buttons that appear at the top of the artwork pane or by getting info and clicking the Artwork tab.
When you sync with the iPod, all this artwork is saved along with the songs, even though you can't see them.
Pet Peeve: "(Disc 1)" and "(Disc 2)". If you've got a two-disc CD, what's the point of attaching these notations to the album name? You get two albums that way, and there really isn't any need to split them. You can keep track of multiple discs using the Disc No. fields. I find it much easier to think of a multiple disc album as a whole.
I have even combined all 4 discs of a box set into one album, as essentially, it's one album split into pieces due to its size.
I have tagged discs separately if I felt there was some significance to the title. For example, John Lennon's box set has 4 discs, each with a different title.
Keeping the number of albums down will make your library cleaner and easier to handle.