Composition - tears of joy

Heard a piece called "Tears of Joy" by Dr J Simon Van Der Walt which can be found on http://jsimonvanderwalt.com/works/tears/.

Ive never heard music in a 15/4 time signature before where only 4 notes are used to create the poly-rhythm it contains... Its made me think about the harmonies im using in some music that im writing in class just now... im going to get this posted up her soon... a song called Heart beat due to its massive attack vibe with the bass drum pounding like a heart in a sub bass format.. 

Tears of joy was topped off not by the fact that it was shortlisted by the society for promotion of music of new music the fact its dedicated to his late mother with the following poem...
Time passes;
we mourn.

Remembering the past,
we cry tears of joy