YouTube will increase the number of ads that some users see between music videos, part of a strategy to convince more of its billion-plus viewers to pay for a forthcoming subscription music service from the Google-owned video site. Bloomberg: People who treat YouTube like a music service, those passively listening for long periods of time, will encounter more ads, according to Lyor Cohen, the company’s global head of music. “You’re not going to be happy after you are jamming ‘Stairway to Heaven’ and you get an ad right after that,” Cohen said in an interview at the South by Southwest music festival. Cohen is trying to prove that YouTube is committed to making people pay for music and silence the “noise” about his company’s purported harm to the recording industry. The labels companies have long criticized YouTube for hosting videos that violate copyrights, and not paying artists and record companies enough.