Control Tips or Context Balloons

While watching the video for the drum mixing I realize there are lots of CTRL + left click or right click or ALT + clicks for various items. To help keep them straight and useful, how about a status line hint or popup balloon that shows the options available.  A certain graphics program puts the options in the status line for reference. It is very handy. Perhaps something similar could be added to Sonar?
 
For example:

 

 
Seems like it would be very useful for the obscure mouse click functions available.
 
Popup balloons would be helpful too but may tend to be more intrusive. Perhaps those could have an option to be disabled.