A flute solo begins the third variation in the theme-and-variations fourth movement of this composer's Symphony No. 8 in G major. The viola introduces the pentaÂ·tonic opening theme of this composer's String Quartet No. 12 in F major. This composer paid tribute to his deceased sister-in-law in his Cello Concerto in B minor. Folk dances such as furiants, dumkas, and polkas comprise his Slavonic Dances. An English horn solo introduces the opening theme of the Largo second movement of this composer's Symphony No. 9, whose 
A flute solo begins the third variation in the theme-and-variations fourth movement of this composer's Symphony No. 8 in G major. The viola introduces the pentaÂ·tonic opening theme of this composer's String Quartet No. 12 in F major. This composer paid tribute to his deceased sister-in-law in his Cello Concerto in B minor. Folk dances such as furiants, dumkas, and polkas comprise his Slavonic Dances. An English horn solo introduces the opening theme of the Largo second movement of this composer's Symphony No. 9, whose Native American and African-American influences stem from this composer's visit to the United States. For 10 points, name this composer of the New World Symphony.