How can I tag 2 songs under the same album?

For example, I have 2 different songs of 2 different composers, both made them for the movie Harry Potter. How can I tag them under for example "Harry Potter OST" so I can easily access all the Harry Potter soundtrack, despite many of it being composed by different people? Would this tag be the name of the album or another tag field?

Thanks.

Compilations from different artists are commonly tagged like this:

Field ALBUMARTIST: Various Artists
Field ALBUM: Harry Potter OST
Field YEAR: 2009
Field ARTIST:
Field TITLE:
Field TRACK:

the descriptions in <> indicate the fields where you have to input the data that distinguishes the individual files.

For some players it is also advisable to set the
Field COMPILATION: 1

But wouldn't it be a big mess of all 'Various Artists'? I have many other songs of Various Artists. How can one differ between all those?

As I said "commonly". But aren't we all individuals?
I myself am not a friend of this way. I would enter "Soundtrack" as ALBUMARTIST or something similar. You are free to enter a grouping name.

What the ordinary player does: it sorts by ALBUMARTIST, then by ALBUM, then by TRACK. By entering data in the fields, you do nothing but supply sorting criteria.

For file organization and naming, I have all my various artist CDs filed under a folder called "Compilatons" and then a separate folder for each album. And each track is named as:
"track number - name of track - name of track artist"

In terms of tagging (and I use foobar2000 and squeezeboxes/LMS) I do the following:

  1. compilation albums all have the tag COMPILATION set to "1". When my players present me with an artist listing for browsing, one of the items in the list is called "Compilations" and if I choose this, it then shows me a listing of all the various album titles.

  2. Album Artist is blank unless I choose to use it for certain purposes. For example, for a Bob Dylan tribute album I might make album artist have a value of "Bob Dylan". This way the tribute album is sorted under Bob Dylan albums when I'm browsing my library to play something.