The symphony has a duration of roughly 17 minutes and is composed in three movements: The composition blends elements of consonant Western hymns, pentatonicism, and polyphonicism reminiscent of Renaissance music.
[5]Contemporary critical reception to Mysterious Mountain was positive and it remains one of Hovhaness's most popular works.
[1][6] In 1995, Lawrence Johnson of the Chicago Tribune said the symphony "still amazes today" and that it "anticipated by nearly 40 years the spiritual, meditative quasi-minimalism of composers such as Pärt, Tavener and Górecki.
"[3] Edward Greenfield of Gramophone noted similarities in the piece to the music of Ralph Vaughan Williams and favorably commented, "'Mountains are symbols, like pyramids, of man's attempt to know God', says the composer, and his spiritual purpose is expressed in the modal writing of the Andante outer movements, with overtones of Vaughan Williams pastoral as well as of Tallis, framing a central fugue characteristically smooth in its lines.
The finale, at the start sounding like 'Tallis Fantasia meets Parsifal', culminates in a chorale leading to a grandiose conclusion.
Harold C. Schonberg, reviewing a Carnegie Hall performance by Leopold Stokowski (on which Hovhaness's symphony shared the bill with the U.S. premiere of Vaughan Williams's Ninth Symphony, as well as works by Riegger and Orrego-Salas), pronounced Mysterious Mountain "well-made and full of delicate sounds", but found it "a not too convincing fusion of his Byzantine with Western elements".
Despite the popular success of the symphony, Hovhaness expressed having "mixed feelings" about certain sections of the piece after its completion.
[8] In a 1987 interview, he was quoted saying:I remember hearing celestial ballet in my head as I lay down to rest from writing the work.