tradition is a noun derived from the latin verb tradere - trado, tradidi, traditum. It is a compound of the preposition trans = over and the verb dare = to give, so it literally means to hand over.
During this handing over from person to person changes occur during decades or even centuries. Fortunately steps of this traditions were documented in handwriting or print.
Tradition also may be the subject of historical research. Doing so on The Blue Stork, dedicated to the Eurogathering in 2004,I noticed how a song changed from Renaissance time upto nowadays.