Do you remember exactly where you were 15 years ago today? I do — I was in London to cover the Led Zeppelin reunion at O2 Arena. The concert was on Dec. 10, 2007, but I spent much of Dec. 9 in the O2’s cavernous foyer, interviewing Canadians who were waiting in line — sorry, queueing up — to claim the tickets they’d bought online after winning spots in a lottery. Naturally, I asked what songs they wanted to hear. One gent was hoping for The Immigrant Song. “Good luck with that,” I replied. Anyway, to mark the 15th anniversary, Zep will be streaming the video of the show — officially released as Celebration Day — for free on their YouTube channel on Saturday. I might take a stroll down memory lane and check it out. But first, join me on a trip through today’s 214 singles, videos, cover tunes, remixes, golden oldies, live clips and holiday tunes — including the usual raft of offerings you won’t find anywhere else. Your Tinnitist-approved tracks are tagged with a (Robert) . Does anyone remember laughter?