7, titled "From the Monkey Mountains" (Czech: "Z opičích hor"), in 1925, three years after he finished his composition studies in Leoš Janáček´s masterclass.
The title of the quartet is somewhat provocative: in Czech, the "Monkey Mountains" used to be the nickname of the Vysočina Region (Moravian Highlands), an area once popular with tourists.
The first performance was not well received, however: in the last movement, Haas added a percussionist, in combination with other unusual musical elements, and this daring experiment was not appreciated by the audience.
The opening theme and tempo of the second movement are closely related to that of the first one, evoking the coach, coachman and horse of the title.
The closing movement uses folk melodies mixed with jazz elements and with unusual application of the percussion instruments.