The commemoration was at 94 Baker Street - the site of the Apple Boutique clothing shop, which was owned in the 60s by the band's company Apple Corps Ltd, the BBC reports. A plaque to Lennon was already on the site, but has now been replaced with one that also remembers Harrison, who died in 2001.
The plaque was unveiled by Rod Davis, the banjo player in Lennon's first band, The Quarrymen, which formed in 1956 and would later become The Beatles.
Meanwhile, the world's first major exhibition about the life of The Beatles drummer Ringo Starr is set to open this summer. Ringo: Peace & Love will open at the Grammy Museum in Los Angeles on June 12 and close in November 2013, before touring cities across the world in 2014.
The exhibit will look at "all aspects of Starr's musical and creative life", including his work as a musician, artist and actor and will, according to a statement, "aim to propel Starr's universal message of peace and love". On display will be never-been-seen photographs as well as letters, documents and original artefacts, including the drum kit Ringo played at Shea Stadium and on The Ed Sullivan Show as well as his 'Sgt Pepper' suit, 'Help!' cape and jacket worn during The Beatles' famous London rooftop concert.
That Hippie Penny Lane