Earlier this week, I put on an LP containing two Mozart symphonies. Usually when I've played it, I've listened to Symphony No. 36. I'd largely forgotten what the B side sounded like, though, so I played Symphony No. 38 instead. At first, I was surprised. Initially, during the first movement, I thought, "Where's the predictable lightheartedness I've come to expect from Mozart? This sounds somewhat grim for a piece that isn't a requiem."
But then, at 3 minutes and 45 seconds into the piece, there it was--the brisk scales that made me think, "Now, that's Mozart."
That's how you know a composer's signature. You might not be able to predict what notes the orchestra will play, but you have a general sense of what the piece will sound like--even if you haven't heard it in years.
