In "Castle House Rag" by J.R. Europe, what section begins at about 2:35?

In "Castle House Rag" by J.R. Europe, the section that begins around 2:35 is characterized by drums and violins introducing a new theme, which aligns with the traits of the D section. This section often features a shift in musical energy, incorporating rhythmically engaging and melodically distinct elements that stand out in the overall structure of the piece.

The use of drums adds a percussive drive that enhances the lively character typical of ragtime music, while the violins contribute melodic richness and complexity. This combination signifies a departure from previous musical passages, marking it as a notable thematic moment.

Other sections in the piece might have different characteristics, such as a more subdued or quiet atmosphere (which would describe the C section), or a straightforward introduction (as suggested in the A section). However, it is the dynamic interplay of drums and violins creating an engaging new theme that distinctly identifies this particular part of the composition, making it the correct choice.