Example- popular songs from the mid 20th century are being revived, reshaped by a current community. What is written today (crappy as we may think some of it is) and is popular today will be adapted and reshaped by future community.

There's certainly nothing in the 1954 definition to exclude that happening, but I'm not sure that is - and I'm very dubious that it will happen in future. I blame the pianola. (And the gramophone, and the radio, and the TV and the iPod, but I like* to think of them all as different forms of pianola.)

*Not really.