Plenty can be said—and has been—for deadlines as a motivator, especially if you tend to put off creative work. (Fewer people seem to know about a study that found that a stressful deadline can actually lower your creativity for a couple of days post-project, creating what the authors called a "pressure hangover.") However, I think it's important that the D.I.N. approach, as applied by John and Paul, isn't exactly a deadline. Rather, it works like an improv game: it operates on the agreement that whatever happens here and now will be our material for now. That opens the door to spontaneity and play—which of course you can hear in the best of the Lennon-McCartney catalogue—and it yields a fantastic, if paradoxical, combination of urgency and low stakes.
My favorite music theory teacher once referred to Mozart as an essentially improvisational composer, a description that explains both his melodies and the volume of his work. You can recognize that a-ha spontaneity in many of his songs, and if you've ever sung his vocal pieces, you've had a delightful sense of discovering places your voice wants to go anyway. A lot of McCartney melodies feel the same way.
I suppose I'm coming to terms with the fact that I haven't been writing as much music as I'd like. I've made notes and starts, and then put them off, and put them off, and put them off. (There has been a whole lot of life happening, so it isn't entirely my fault, but still.) Earlier this week I pieced together some ideas—a song that has taken so long that bits of it are in three different notebooks—and sat down to "steamroll through." I didn't get it done done, but I made more progress than I have in a while. Perhaps more importantly, it seemed to throw open the door to other work—the opposite of a pressure hangover!—and by last night I had two new demos.
I'm going to find a new place for the postcard.