+1 on track number

[SamFire7645]

I have a large playlist, need to +1 on track so I can add more songs at beginning of playlist.
-> 1
1 -> 2
2 -> 3
3 -> 4
4 -> 5
5 -> 6

[ohrenkino]

Create an action of the type "Format value" for TRACK
Format string: $add(%track%,1)

Did you know that you can load a playlist into MP3tag with drag&drop from the explorer,
add further files with drag&drop from the explorer,
move them around in the files list with drag&drop while pressing Alt
and then save this new playlist with the files in the same order as displayed in the files list?
.. so there would not be the need to modify the track number.