Complex sentence: For some time, Manson had been predicting blacks would rise up in rebellion in America's cities; now, he explained that The Beatles, too, were making that prediction, on their then-new "White Album".
Split into simpler sentences: For some time, Manson had been predicting blacks would rise up in rebellion in America's cities. Now, he explained that The Beatles, too, were making that prediction, on their then-new "White Album".