2062: Questions regarding sort order in track view

[djdd]

In a new installation the Music > All tracks > List view is sorted by

• Album (indicated by superscript 2)
• Title (indicated by superscript 4)

First question: What are the sort field 1 and 3

Second question: I can change sort order to Artist, by clicking the artist column header, but how can a add a second sort order (e.g. Title)?

Thanks,
Dieter