Philip Glass (born January 31, 1937) is an American composer. He is widely regarded as one of the most influential musicians of the late 20th century. Glass's work has been described as minimal music, having similar qualities to other "minimalist" composers such as La Monte Young, Steve Reich, and Terry Riley. However, Glass has instead described himself as a composer of "music with repetitive structures", which he has helped evolve stylistically.

Glass describes himself as a "classicist", pointing out he is trained in harmony and counterpoint and studied such composers as Franz Schubert, Johann Sebastian Bach, and Wolfgang Amadeus Mozart with Nadia Boulanger. Aside from composing in the Western classical tradition, his music has ties to rock, ambient music, electronic music, and world music. Early admirers of his minimalism include musicians Brian Eno and David Bowie. In the 1990s, Glass composed the aforementioned symphonies Low (1992) and Heroes (1996), thematically derived from the Bowie-Eno collaboration albums Low and "Heroes" composed in late 1970s Berlin.  Glass has collaborated with recording artists such as Paul Simon, Suzanne Vega, Mick Jagger, Leonard Cohen, David Byrne, Uakti, Natalie Merchant, S'Express (Glass remixed their track Hey Music Lover in 1989) and Aphex Twin (yielding an orchestration of Icct Hedral in 1995 on the Donkey Rhubarb EP). Glass's compositional influence extends to musicians such as Mike Oldfield (who included parts from Glass's North Star in Platinum), and bands such as Tangerine Dream and Talking Heads. Glass and his sound designer Kurt Munkacsi produced the American post-punk/new wave band Polyrock (1978 to the mid-1980s), as well as the recording of John Moran's The Manson Family (An Opera) in 1991, which featured punk legend Iggy Pop, and a second (unreleased) recording of Moran's work featuring poet Allen Ginsberg.  Glass had begun using the Farfisa portable organ out of convenience, and he has used it in concert. It is featured on several recordings including North Star and on "Dance No. 1" and "Dance No. 3".

Using a quote from the above article, answer the following question: What did Philip Glass do as a "classicist"?
Glass composed the aforementioned symphonies Low (1992) and Heroes (1996),