The Symphony No. 4 in G major by Gustav Mahler was written in 1899 and 1900, though it incorporates a song originally written in 1892. The song, “Das himmlische Leben”, presents a child’s vision of Heaven. It is sung by a soprano in the work’s fourth and last movement. Although typically described as being in the key of G major, the symphony employs a progressive tonal scheme (‘(b)/G–E’).Mahler’s first four symphonies are often referred to as the “Wunderhorn” symphonies because many of their themes originate in earlier songs by Mahler on texts from Des Knaben Wunderhorn (The Youth’s Magic Horn). The fourth symphony is built around a single song, “Das himmlische Leben”. It is prefigured in various ways in the first three movements and sung in its entirety by a solo soprano in the fourth movement.---A listening guide of Symphony No. 4 - Intro with Lew Smoley.