title: Playing sine wave for unknown time
body: <p>Whole day I was looking for some tutorial or piece of code, "just" to play simple sin wave for "infinity" time. I know it sounds a little crazy.</p>
  
  <p>But I want to be able to change frequency of tone in time, for instance - increase it. 
  Imagine that I want to play tone A, and increase it to C in "+5" frequency steps each 3ms (it's really just example), don't want to have free places, stop the tone.</p>
  
  <p>Is it possible? Or can you help me?</p>