Discuss in detail how Xian employs a traditional Western key structure and harmony in the first movement of the Yellow River Piano Concerto.

Having spent time in both Russia and France, Xian, who was born in China, draws on a rich musical palette, mixing traditional Western influences with oriental origins in the Yellow River Piano Concerto. The first movement utilises functional harmony, opening in D major, before immediately progressing with a iib-V-I perfect cadence in bars (b.) 2-6. Xian also frequently uses pedals, another traditional technique in Western music. For example, Xian ends the piece with a perfect cadence after a 6-bar long passage (b. 104-110) of a recurring tonic pedal in the double bass part. Furthermore, Xian uses a Western key structure by beginning b. 51 (Section C) in the relative minor (B Minor). This section is widely diatonic, straying from oriental harmonic conventions. One of the most prominent examples of Xian employing traditional Western harmony is his usage of the augmented 6th chord in the piano in b. 80. The application of this chord was proliferated by European composers in the Classical and Romantic periods, and was rarely used by their Chinese counterparts.