Allow the user to choose which musical key he is composing in. Depending on the key, accidental notes will be displayed accordingly in the pattern editor. For example if he is composing in F major, all A# notes in the pattern editor will be displayed as Bb. However if he is composing in B major, A# will display simply as A#.

This feature would simply allow the user to "reskin" the OpenMPT interface to display some sharp notes [#] as flat notes [b] depending on the musical key he is composing in.

Currently it's a little confusing for new users to compose in musical keys that use flat notes. (Seeing an A# in the pattern editor when you meant to enter Bb can be slightly counterintuitive.) This feature will also make tracker patterns more readable and easy to navigate.

In addition an option can be included in the context menu of an accidental note to toggle between displaying as a sharp or a flat. This way the user isn't "locked into" whatever display mode he chose, and he will have more freedom.