Your definition of music (whether for arguments sake or not) is very, very shallow. A composition does not require a distinct melody to be a compostion.
Its funny that you say, any organised collection of samples or sound effects, as the broadest definition of music is simply 'organised sound.'
Sheet music is one of the worst and inaccurate methods of communicating and preserving music, due to factors like the insane level of difficulty and restrictions in notating a physical linear score (relaying the composers emotional intentions, notating extended techniques effectively, writing with scales that arent built on 8 notes etc).
Many people have attempted to overcome a lot of the restrictions inherent in scoring (see: graphic scores of the avant garde, non linear scoring
http://andrewhearst.com/blog/2006/02...r_george_crumb) etc, but recorded audio remains the best method of preserving and communicating a composition.
I don't see why it keeps coming back to Skrillex (guy must be losing a lot of sleep over this thread), but eh. Here's a few examples of harmony, melody, counterpoint in his music.
https://www.youtube.com/watch?v=-e_3Cg9GZFU
https://www.youtube.com/watch?v=YJVmu6yttiw
Eg - bangarangs aroung Gm, with clearly defined melodic parts (G Bb, C Eb in main section). Just because a sound has unusual harmonics in it, doesnt mean there isnt an underlying melody thats discernable.