SERIES PREMIERE: Martin Scorsese had such fun teaming with Mick Jagger to concoct Vinyl, HBO’s colorful dramatic time trip back to the rock scene of the early 1970s, it was natural HBO and Scorsese would embark on a spinoff series while the iron, and the series, was hot. Actually, Shellac is a prequel series, because before there were the 33 1/3 rpm 12-inch records made of vinyl, there were the 78 rpm 10-inch records made of brittle shellac. Those were the days, my friend, and Shellac starts midway through the era, in the late 1930s, when Victrolas were all the rage. Watch, in the opener, for American Idol winner Ruben Studdard as Fats Waller, recording his raucous version of “Your Feet’s Too Big” in 1939.