Even if you scorn Boomer myth-making, the 50th anniversary of “Revolver” — perhaps the Beatles’ best album — is a big deal. It not only sent the band in a new direction, it showed new possibilities in rock music. Look at the state of rock music in the 21st century — when so much of popular music is about artfully recycling existing tropes and styles — and it can be hard to see what the fuss was about. But the album was groundbreaking for a bunch of reasons, and it’s aged better than almost any of the great records of the era. One way that “Revolver” immediately stood out was its eclecticism. The album that preceded it, “Rubber Soul,” saw the band mostly in acoustic-folkie mode, and the one that followed it, “Sgt. Pepper’s Lonely Hearts Club Band,” was mostly expansive, psychedelic, and orchestrated. Both are masterpieces. (The hype around “Sgt. Pepper’s” has led some to dismiss it, but go listen to it sometime — even overlooking the backstory and concept-album pretensions, it’s packed full …