Expose main volume slider in main window or title bar

[avila]

After setting the levels of individual audio tracks I often wish to lower and raise the overall volume depending on the activity I am doing and I rarely adjust individual tracks after that. With that I believe it would be an improvement to expose the main slider so that less clicks are required, similar to the play/pause button. I think of a slider at the top of the main frame or, if possible, on the title bar itself.

As an idea, on the title bar the slider could expand vertically when clicked and it would be interesting if it would be exposed to mouse wheel events (no previous click necessary).

Again, this is very low priority, but maybe other users think alike. (If this has been already discussed, apologies)