I finally reached the point today when I switched off my music whilst working. This is a serious sign. I have warned the editor that I may be a touch late with the manuscript but he was drunk, and I was tipsy, and he can't remember the far more serious business of the title of the next Star Wars film which was revealed to him that evening but which he now claims to have forgotten again. I'm concerned that his fervent desire to forget the SW title (don't ask) means he has also blanked my confession re the deadline.
Trouble is, there is no realistic way to speed up: my days are totally solid with some other very ugly deadlines, and I don't have any free free time until the end of August. So now I'm switching off the music to ensure the only sound is the keyboard clattering with quickly formed words. Except, obviously, right now I'm typing this instead of the novel. Argh!!!!