How do I move a track from one album to another?

Head to your discography, and view the album containing the track you want to move, and click the Edit button beneath the title.
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In the album editor, select the track and then click the "detach" link at the bottom of the track pane. Save the album.
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Head to the discography, view the newly-free-floating track, and click Edit.
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Check the "part of an album..." drop down, select the new album (which must be published, not a draft, to appear).
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When you’ve selected the right album, don’t forget to click "Add to Album"! Voilà.