In the wake of the most recent study to pour cold water on the so-called Mozart Effect, NPR’s Alix Spiegel looks at the history of how the idea that playing classical music can make you smarter took hold.  She re-visits psychologist Francis Rauscher who conducted the original, modest, narrow-focus study on spatial intelligence in 1993 — and who made international headline news with her single-page report, touched off a record-industry frenzy and eventually received death threats from rock music partisans.