I only discovered the music of the Finnish composer and conductor Leif Segerstam a few months ago. His handwritten scores can be quite a mess, but his music is always interesting and engaging. His music is usually very free. The individual parts do not always line up together, in fact they very rarely do. Perhaps the freedom allowed to the performers is what draws me to his music since I've been working on that same issue in my recent music. Anyway here is a video of Pia Segerstam (cello) and Christophe Sirodeau (piano) performing Leif segerstam's Noem No. 8 for cello and piano. Pia Segerstam is the daughter of Leif Segerstam and if I remember correctly Christophe Sirodeau is her husband.
http://www.youtube.com/watch?v=6dj_gSOpBDg