title: How to make return to previous Activity with on back pressed?
body: <p>I have an activity called <code>MainAct</code> and <code>SubAct</code>. <code>MainAct</code> is the parent of <code>SubAct</code>. </p>
  
  <p>In <code>SubAct</code>, I am playing a music background. In order to stop the music when I press back button, I implement this code below :</p>
  
  <pre><code>@Override 
      public void onBackPressed(){
        if (tick != null){
            if(tick.isPlaying())
                tick.stop();
  
            tick.release();
        }
   }
  </code></pre>
  
  <p>With that code, the music is stopped as I expected. but the problem is I cannot go back from <code>subAct</code> to <code>MainAct</code>...</p>
  
  <p>I know this is trivial, but can you show me the correct way to do this?</p>