The first page of the Music for Cello and Piano (1955) by Earl Brown. You can download the complete href=”http://www.analogartsensemble.net/blog/Music%20for%20cello%20and%20piano%20(1954-55).mp3″>mp3 from ANABlog.
From this blog you can also download various Maderna compositions in mp3 format.
This musics and many others are available at the Avant Garde Project site.