So I have a 4-disc album of approx. 150 tracks that I'm dropping into iTunes. The problem is, only the track numbers are in the metadata, not the disc numbers. So in iTunes that puts all four track 1s together, followed by track 2s, etc. Changing it in iTunes will be a nightmarishly tedious task of right-clicking each and every one individually to change them.
How can I mass edit them in MP3Tag? I tried already, changed all of the disc 1 tracks, but even after saving, nothing happened. It remains the same in both File Explorer and iTunes.
Can you post a screenshot and describe what you did to change all of the tracks? If you already have these tracks in iTunes you will need to remove them from that library, make the updates, then add them back again. Or use a script to refresh iTunes.
What do you mean? You don't see the field DISCNUMBER in those applications? That would be a feature of the player, wouldn't it?
To get data into DISCNUMBER use the track numbering wizanrd Ctrl-K.
To get all that data visible into the player that does not show the DISCNUMBER, you could contemplate merging DISCNUMBER and TRACK into 1 field so that first track from first disc gets track number 101, the second 102 and so on and the first and second from disc 2 get track numbers 201 and 202 etc.
To get that, provided you have data in DISCNUMBER and TRACK try an action of the type "Format value" or Convert>Tag-Tag for TRACK
Format string: $num(%discnumber%,1)$num(%track%,2)