YouTube will launch a new subscription music service, the company acknowledged Tuesday after being dragged into a public dispute over royalties that will result in the blockade of some independent artists’ music videos. The Google Inc.-owned video site said in a statement that it is “adding subscription-based features for music on YouTube” and that “hundreds of major label and independent artists” have signed on. The paid service – to be launched within a few months – will likely allow playback of videos without ads and allow for offline playback on mobile devices. That’s according to two people familiar with the matter. The people weren’t authorized to speak publicly and spoke on condition of anonymity. The people also confirmed that a small number of independent artists who had not agreed to new deal terms will have their videos blocked in some countries starting in a few days, even on the free version of YouTube.