Hi Manhong, it's squishy to form an opinion related to violation of a license and toleration of sensible modifications and sometimes even to distinguish between theft and fortuitousness. If you wrote a song named "love song" composed of holding the note c for 1000 beats and after that holding the note c# for another 1000 beats at 120 beats per minute and a year later I write two songs and name both "love song", too, one composed of holding the note c for 1000 beats at 120 beats per minute and the other one holding the note c# for 1000 beats at 120 beats per minute. Would it make sense to argue related author's rights? Sometimes disputes make no sense. Several factors must be taken into account and often common sense can be used to rate, if it's worth to argue. Regards, Ralf