Reworking Old Songs - Ship of Theseus

Subject: Reworking Old Songs - Ship of Theseus
From: David W
Date: 04 Dec 18 - 09:59 AM

When does an old song cease to be the old song and become a new song?

If you change 25/50/75% of the notes, can you no-longer call it the old song, for example. Or is it always the same song?

If I advertise playing a song, then play it with 95% of the notes changed, is it a con?