Vevo and four other content sources—Disney, Disney XD, the Smithsonian and the Weather Channel—have joined the ranks of Apple TV apps. The launch makes Vevo’s catalog of music videos, which the company says numbers 75,000, available on demand to Apple TV users, as well as the company’s original programming— “Lyric Lines,” “The Comment Show,” “Stylized” and “Tour Exposed”—and its curated Vevo TV channel that it launched in March. The expansion onto Apple TV is part of a larger strategy for Vevo of correcting the narrow margins it operates under due to a reliance on YouTube’s platform. At launch the Vevo Apple TV app is available in the United States, Canada, Australia, New Zealand, the United Kingdom, Brazil, France, Ireland, Italy, Spain, the Netherlands and Poland. In June, Apple added the…