When it comes to niche classical music, there are many options. Here are some composers and works that may interest you:

- John Cage: His works are often unconventional and include the use of noise and other unusual sounds to create music. For example, his 4'33'' is a recording of four different musicians, each playing a unique piece of music, but the full track is not heard.

-Philip Glass: His compositions are often minimalist, using simple melodies and repetitive rhythms. For example, his "WaterMusic" is a work composed of a series of different water sounds.

-John Adams: He was an American composer known for his complex orchestral works. For example, his "The ChairmanDances" is an orchestral piece performed by two different orchestras.

-Frederic Chopin: He was a Polish composer known for his beautiful piano music. For example, his "Ballade No. 1 in Eminor, Op. 64" is a very famous piano piece.