Western Train Suite consists of 7 short parts: Magic, Fast, Slow, Fast, Dissonating, Slow, Magic. Each part type (for example, Magic) has its own unique parameters. This is why different parts of the same type resemble each other. Each new part starts in the key, where the previous part left off. This is the result of adding a new function of creating multi-part compositions in QGen2 generator.
Since the Emerald train I also added some general functionality (punctum rhythm of dotted crotchet and a quaver, reprises inside a piece and some bug fixes).
Please see description of QGen2 algorithm (with sources) used for generation in the Software development section.