Some experiences etch themselves so sharply on our memory that they form islands of clarity in our recollection For me such a momentous occasion took place one night in California many years ago when I lay awake listening to the rapturous strains of a mockingbird singing from an invisible location in one of the tall trees that were dotted around the suburban neighbourhood I dont suffer from insomnia  it was the exquisite artistry of the singer that kept me awake As I followed his intricately woven melodies I found myself drawn into an unexpected aesthetic environment In order to follow the patterns that issued from the bird I had to call on my experience of jazz and Indian classical music The bird had me convinced that I was being treated to an ad lib performance of the most breathtaking improvisational acrobatics I groaned and I cheered as one improbable musical variation followed another through the open window where I lay listening until finally I fell asleep