If you pay close attention to Mozart’s music, you know about the “K” numbers that accompany his compositions. Well, Chopin can do Mozart one better. He’s got K times two — “KK” numbers.
As Ludwig Köchel was to Mozart, so Krystyna Kobylańska was to Chopin. They were both musicologists who created catalogs that place these composers’ works in logical order.
Why was that necessary for Chopin? His works have always had opus numbers to help us keep track. Well, some but not all. Opus numbers were assigned only to Chopin’s published pieces.
In the 1950s and 60s, Krystyna Kobylańska was a curator for the Chopin Museum in Warsaw. She went on to compile all of Chopin’s known manuscripts, published and unpublished. That led to a thematic catalog of his music. In addition to the pieces with opus numbers, Kobylańska accounted for Chopin’s 39 published pieces that were not numbered, as well as his unpublished sketches, arrangements and lost or inaccessible works.
She gave these pieces numbers—now known as KK numbers, for “Krystyna Kobylańska.” So, for example, we can now refer to the Sostenuto in E-flat, written in 1840 and published in 1955, as KK 1237.
If only Krystyna Kobylańska had replaced Chopin’s opus numbers too. They are often WILDLY out of chronological order. Sorting through that numbers game sounds like a good job for someone whose last name begins with K. - Don Lee