Such is the power, cachet and sheer entertainment value of “Bohemian Rhapsody,” the Freddie Mercury-written piano spotlight ballad turned epic arena rock triumph, that Queen’s fourth album is nearly overshadowed by it. But 1975’s A Night At The Opera, in aiming to be all things for all people, created a world of its own that most actual concept albums couldn’t reach. Brian May’s winsome “‘39,” the John Deacon-written easy groove of “You’re My Best Friend” and Roger Taylor’s earnestly theatrical “I’m In Love With My Car” and more easily showcase everyone.