The popular character of the new world symphony can be traced to the composer's use of often found in folk music.

Syncopation , pentatonic scales  and modal scales.

Explanation:

Syncopation in music represents an alternation of different rhythms that occurs suddenly so as to break the rhythm's regular flow. It is used in dance music and pieces rich in syncopation induce a desire to move to the music.

Pentatonic scales are music scales containing 5 notes per octave (Ancient Greek pente meaning five) and they root from ancient civilizations. This scale was discovered naturally through human's innate sense of music.

Modal scales can be derived from one major scale with a different starting tone. One of the most common modes is Aeolian, which starts at the sixth major scale tone.

All of the above are the specific elements present in romantic music (XIX century).

modernism is a 20th century movement