I noticed in the run up to Christmas a veritable plethora of 50th anniversary record releases. The marketing Johnny's having a ball re-packaging the Beatles, Kinks and Led Zeppelin (to name just three) to tempt and test the resilience of fan's credit limits. 
Which brings me to, 50 years ago tomorrow, the debut album by Led Zeppelin hit the record stores of America. Recorded the previous October, a few gigs in Scandinavia and small venues in the UK (only 13 to be precise) followed. Concerts in the US were underway by the time of the LP release, having been signed by Atlantic Records founder Ahmet Ertegun who apparently hadn't even seen them play. This American record deal may explain why the album curiously wasn't released in the UK until March 28th. <link>
No doubt copies of the record were played on British radio during those 2 months, but it's likely the first notes heard (first song, Side One) of Led Zeppelin 1, were these: 
Jimmy Page's guitar riff with John Bonham's drums on 'Good Times, Bad Times' >

Wanna a video from 1969? Here's the track that followed this on the LP - recording from German TV Beat Club show: 'Babe, I'm Gonna Leave You' - still bloody excellent !