On 9/5/2013 I de-linked my Google+ Page from my channel caused the channel to close, unbeknownst to me, which Mr. Andy S. M. Robert eloquently explains in this video, so you may need to subscribe again. Sorry for the inconvenience, but it was part accident on my part, part YouTube / Google's. P.S. I am not angry in this video - it was hot in the car and recorded with my phone. :)
To listen while using other apps, switch the player to Picture-in-Picture (PiP) during playback — it keeps playing in a small floating window (the screen stays on).
To listen with the screen fully off, in-browser playback stops by YouTube's design. Open the video in the YouTube app to keep listening where background playback is supported (e.g. with YouTube Premium).
Open in YouTube app