Why are these double notes labeled 'contrary motion'?

Question

In my PDF version of Slonimsky's Thesaurus, there's a section called 'Double Notes in Contrary Motion' on page 215. Can anyone explain why he is calling these contrary motion? To me, apart from the very last example no. 343 (at the bottom of page 217), they all seem to be either similar or parallel motion. I'm sure I must be missing something obvious.

Answer 1

Contrary motion simply implies that one musical line is ascending while the counter melody is descending.

Answer 2

"Contrary motion" refers to a type of musical motion where two parts move in opposite directions. In the context of double notes, this means that while one note of the pair is ascending, the other note is descending, or vice versa.

For example, if you have a pair of notes where one is moving from C to D (ascending) and the other from E to D (descending), this creates contrary motion. This type of motion can create a more dynamic and interesting harmonic texture, as it provides contrast and balance within the music.

In summary, double notes are labeled as "contrary motion" when the notes in each pair move in opposite directions, adding richness and complexity to the musical passage.