Muslims have Mecca, Jews have Wailing Wall and folk-rock aficionados have Laurel Canyon, the L.A. neighborhood that gave birth to jangling 12-string guitars and the heavenly harmonies of The Byrds, The Beach Boys, Buffalo Springfield, CSN and The Mamas and the Papas, to name a few. It’s also where, according to Andrew Slater’s note-worthy “Echo in the Canyon,” Bob Dylan found the inspiration to go electric.