Scott Smitelli uploaded a total of 82 test videos and received 35 Content ID emails in the name of science: testing YouTube’s Content ID system. He reversed the audio, shifted the pitch, altered the time (without changing pitch), resampled (pitch and time), added noise, messed with the volume, chunked it up into pieces, and fiddled with the stereo fields. In the end, he found both amusing and frustrating results.
He did his tests about a year ago. Google appears to have caught on and disabled his YouTube account, who knows if they’ve addressed some of the holes in the system he found.