You recognise it the second it comes in: the gentle cymbals, the buttery-smooth keyboards, the lush guitar chords. When Steely Dan kicks into ‘Deacon Blues’, everything seems so crystalline and perfect that it almost doesn’t seem real. Filled with nuance but never too complex for the average listener, ‘Deacon Blues’ is an easy entry point into the jazz-rock weirdness of Steely Dan. But its place in the wider world stretches beyond an introducti…