I posted this awhile ago, got no notice. But in reading the Reference Guide, the documentation says one thing and the program, Sonar Plat, does another thing:
Page 1370: "In the Track Inspector, force Sonar to play the trumpet track a whole step lower by entering -2 (negative 2) in the Key+ field and pressing ENTER".
Try it for yourself. If you are not accustomed to sonar's current wild state, you'll be shuddering for half an hour.
Of course the REAL design flaw is the choice of number keys as adamantine choices for screen sets.