I was just looking at Audacity's display of Chordino (for the first time...) and noticed that it's quite neat. especially the fact that you can collapse it is quite cool. At the same time, I've found it quite confusing to have several annotations in one pane in Sonic Visualiser. It would be nice to have collapsable panes in SV or a different concept: a "strip" that can contain only one 0-dimensional annotation, but is much flatter than a pane, so you can have many on top of each other. A similar concept is realised in the MIREX visualisations.