What on earth is going on at NaNoWriMo HQ? Here's a high level summary compiled by an anonymous community member.
Noveling music
Noveling music is music that a writer will listen to while they novel. This music usually helps them concentrate, increases their typing speed, and sets the mood for the scene that they are writing. On the Fact Sheet under Author Info, there is an option for NaNoWrimo participants (Wrimos) to fill in their favorite songs, artists, and genres that helps them write.
Musical tastes vary widely from author to author. Some writers prefer music without lyrics due to lack of words outside their novel, but this is nowhere near universal. Others prefer songs with lyrics, especially familiar songs, as the background music can help with focus.
There is an entire forum dedicated to Noveling music called NaNo Soundtracks, where countless WriMos discuss their favorite noveling music, find new favorites, and talk about essentially anything that can connect music with noveling. Some regional forums have threads that talk about favorite novel music.
There is noveling music written specifically about NaNoWriMo called WrimoSongs (NaNoWriMo Songs). However, most of these songs are usually best listened to when you need motivation or just something to laugh at when NaNoWriMo comes to mind. Even then, some Wrimos listen to it while noveling.