Philip Glass is a contemporary (b. 1937) American minimalist (he rejects this term) composer. He authored operas, theatre works, ten symphonies, concertos, chamber music (string quartets) and film scores, such as the magnificent A Brief History of Time for Errol Morris's documentary (more on that here). To me, this is the music of the Physical Universe and, which is the same thing, of Mysterium Tremendum. You can play it here to set yourself in the mood:
I still remember this intimate embrace of the unknown with a promise of revelations, of enlightenment supplanting knowledge, of understanding blossoming in wisdom, of inner, intemporal, everlasting peace at last, that I felt when first hearing this music. I knew I would spend the rest of my life trying to touch with my brain what my soul had fleetingly grasped.
Some renditions of Glass' work, like this passage[1] from his String Quartet No. 5 by the Kronos Quartet (for which this was written), seem to open a door to another dimension.
Lesser known. A dissonant precursor to his minimalist style; two movements with gestural repetitions. Anguishing music. He would leave this style in pause for almost two decades. Can be listened here.
His second masterpiece in this genre, five movements with dedications, rich in cyclic themes and emotional gravitas. A beautiful rendition is by the Kronos Quartet. A favourite passage is from the String Quartet no. 5: V.
A three-movement work commissioned by the Kronos Quartet, richer than usual, with surprising moments like a long unison passage in the third movement alternating between 7/8 and 4/4 meters.