If Sandhyavandanam means invoking the late-evening twilight hour as per Hindu rituals, then Bismillah Khan used to perform it in his own way with the musical pipe. As the sun would descend beyond the Ganga in his native Varanasi, the shehnai icon would play the humble double-reed instrument. A classical raga or a folk tune will emerge from it—and the notes waft in tandem with the famed arati on the banks of the broad river that lines the pilgrim city in the northern Indian plains.