Recently finished a professional stage production review based upon various music styles of Broadway Show Tunes, here in Florida. Because of the fact that some songs had to be pitched based upon each singer's range, the plus/minus buttons for the transposer were indispensable. Add to that, at all times there is an on screen indication of where the keyboard is currently pitched without having to push a button to find out. In addition, The programmable presets were also an asset that could not be done without! Although the initially ordered unit malfunctioned, the salesmen at SAM ASH MUSIC quickly rectified the situation with a new 2nd unit that continues to function up to specifications! Brilliant CASIO!!