All of this, and much more -- key/scale-specific highlight/stripes,
labeling and coloring notes by scale degree, display of notes' chord
functions (root, 3rd, 5th, etc) -- is available in my fork of Rosegarden
at
https://sourceforge.net/u/thanks4opensrc/rosegarden/ci/thanks4opensrc_devel/tree/
Assuming you are in the matrix editor, the best you can do is
highlight the I (or i) chord. Go to View > Highlight > Highlight
Triads. That will darken the 1 3 and 5 degrees of the scale in the
current key.
If that's not good enough, feel free to open a feature request.
Philip can
How do I set a scale in Rosegarden? In the web app Bandlab, you can select
a scale and it will show you it on the keyboard. How would I do this in
Rosegarden? I don't want to use Bandlab, as it isn't advanced enough, and
doesn't have a music sheet option called Notation Editor in rosegarden.
