A feature I used very often in Amarok 1.4 was the ability to make an arbitrary selection of tracks in the playlist and then use the context menu on a field to "Write $foo for selected tracks" or "Edit $field for selected tracks". It is phenomenally useful for fixing albums that have been mangled by picard or similar. Moreover, it has proven useful for allowing me to write blank titles for an entire album (removing a tedious step in excising transliterations) or the artist (a lot of soundtracks credit e.g. the movie/game title as the artist, which is tremendously boorish of them when there are a lot of people who pulled sound duty). Reproducible: Always
One can select multiple tracks and edit with the standard Edit Track Details dialog; the fields left empty are not written, so one can write the desired field only for the tracks (2.9.71, has been like that for a decade, I guess)