Music industry types must have had been reaching for their tranquilizers this afternoon, following a report that Apple is in early stage talks to buy Spotify. The report spread quickly, as these things do, and some thought it made  a lot of sense.  So Apple, maker of the world’s most popular music device, the iPod,  which already owns the No.1 music  download retailer iTunes, would be buying Spotify –the much-loved and critically acclaimed music streaming service, just as it’s finalizing deals to launch in the U.S.? This would be too much to handle for many music executives, who think Apple already holds way too much power.