Last year while visiting NZ (which I loved)I bought a CD of Dame Kiri Te Kanawa singing Maori songs. There are other voices and instruments as well as hers. The booklet has notes about each song; the notes for Po Ata Rau (Now is the Hour) say that it is adapted from a 1913 piano solo composed in Australia. Maori musicians changed the rhythm to 3/4 and added Maori words....and so on. I can provide the notes in full if anyone is interested.
Cheers
JennieG who had a Kiwi grandmother