The relevant puzzle answers are the following:
THE FIRST NOEL
THE RISE AND FALL OF THE THIRD REICH
KEPLER'S THIRD LAW
PAS DE DEUX
Each of these is the title of a creative work of some kind. Creative works, of course, are inspired by the nine muses, and as it happens each of these works would have been inspired by a specific one of the nine muses. Extract a specific letter from each muse's name as clued by the title of the corresponding work:
THE FIRST NOEL: 1 / sacred music: Polyhymnia --> P LAST SONNET: last / lyric poetry: eratO --> O FOUR QUARTETS: 4 / epic poetry: calLiope --> L FOUR ROOMS: 4 / comedy: thaLia --> L THE RISE AND FALL OF THE THIRD REICH: 3 / history: clIo --> I OCTAVIA: 8 / tragedy: melpomeNe --> N KEPLER'S THIRD LAW: 3 / astronomy: urAnia --> A KEGELSTATT TRIO: 3 / music: euTerpe --> T PAS DE DEUX: 2 / dance: tErpsichore --> E
This spells POLLINATE, the meta answer.