Is cross-hand playing defined as moving the left hand over the right hand to play a high melody?

Cross-hand playing is indeed characterized by the left hand moving over the right hand to play a melody, typically in higher registers on a keyboard instrument. This technique allows for a more intricate and expressive performance, enabling the musician to reach notes that might otherwise be difficult to access. It is a stylistic choice used across various genres, not limited to classical music.

The other choices are not accurate in defining cross-hand playing. The practice is not confined to classical music, as it appears in modern compositions as well. The definition itself is straightforward and does not pertain solely to a particular genre or time period, making the assertion that it only occurs in classical or modern music incorrect. Thus, affirming that cross-hand playing involves the left hand crossing over the right to produce a high melody correctly aligns with the established definition of the technique.