Q: Is there a simple way I can associate one image as the album art for every song in my iTunes music library?
A: Although it is not possible to have iTunes simply use a single image for every song by default, you can assign an artwork image to multiple tracks at once.
To do this, simply select the tracks that you want to apply an album artwork image to. To select ALL tracks in the current view, you can use the Edit, Select All option. Once the selected tracks are highlighted, simply choose File, Get Info and you will be presented with a dialog box that will allow you to edit the properties for all selected tracks.
An artwork image can either be dragged into the “Artwork” box, or you can paste an image in from the system clipboard by clicking on the Artwork box and pressing CTRL-V (Windows) or CMD-V (Mac) to paste the clipboard content into it. Clicking OK will then apply the assigned artwork image to all tracks, replacing any artwork that may have previously been present.
Another method of assigning artwork is to use the artwork window in iTunes itself. To do this, ensure the window is displayed by choosing View, Show Artwork and that it is showing the artwork for “Selected Item” instead of “Now Playing” (you can change this by clicking on the title of the artwork window). You can then select multiple tracks and drag or paste the artwork into the artwork window. Note, however, that this will not replace existing artwork, but only add the artwork image to the selected tracks as an additional image which will appear in the “Artwork” tab of the track properties.
Also note that either procedure will embed the artwork image in every selected track, so it may take a few minutes to run on a large library, and it will slightly increase the size of each file by approximately 40-50KB (depending upon the resolution of the artwork image). These added artwork images, if transferred to the iPod, will also take up additional space on the iPod since each image must be stored individually in the artwork database on the iPod, even if they are all the same image. Each image takes up approximately 100KB per track on a 5G iPod, or 24KB per track on an iPod nano.