One of the advantages of staying up to the wee hours is finding obscure movies on cable. Early Sunday I came upon a real oddball: “The Great Gabbo” (1929), with Eric von Stronheim in an over-the-top performance as a deranged, coffee-drinking ventriloquist. If that’s not enough reason to seek this one out, there’s a host of Busby Berkeley-ish musical numbers. They don’t make movies like this anymore.