Sound of Inline 4 motorcycle sport bike. Not the high rake supersport with loud aftermarket pipe, but the stock pipe on a comfort sport bike.
It burbles like a purring cat when idling, and comes to life when accelerating; with a mix of high revving engine, the intake and exhaust noise, the transmission whine, and the subtle tinkle noise of the chain going over the sprockets. Its like a beautiful cacophony.
I hate gas leafblowers, those should have to be electric only.