how to change music tonality in runtime? On windows usualy for karaoke purpose some audio cards provide possibility to change tonality on fly, is it possible under Mac ? 

Is ther any additional software which can do it ? or maybe terminal command ?
Have a look at Capo.
From their Website: 


  Pitch Adjustment
  
  Capo lets you adjust the pitch of your songs—so you can change their
  key or fine tune them to match your instrument.