Mezue ahịrịokwu na-esonụ: Clark bụ onye na-akụ ụbọ akwara na Denver Philharmonic Society mgbe ọ bụ nwa agbọghọ. N'afọ 1915, ọ rụrụ na
Panama-Pacific International Exposition na San Francisco, na-egosi ụbọ akwara maka ụlọ ọrụ Rudolph Wurlitzer. N'afọ 1917 na 1918 ọ gara njem North America na onye Switzerland cellist Elsa Ruegger. N'oge oge 1919-1920, ọ bụ onye na-akụ ụbọ akwara na Seattle Symphony Orchestra. O depụtara ma hazie Charles Wakefield Cadman's "From the Land of the Sky Blue Water" maka ụbọ akwara. Ka ọ na-erule n'afọ 1928, a na-akpọ ya "onye na-akụ ụbọ akwara kasị mma n'America". Na 1931, o jere ozi na ngalaba nke ụlọ akwụkwọ oge ọkọchị nke Mount St. Mary's College, na-akụzi ụbọ akwara.