ABBEY ROAD OPENS ITS DOORS

The Beatles rest between takes in Studio Two at Abbey Road in London during the recording session for the single 'She Loves You' on July 1, 1963.

At Abbey Road Studios, four visitors are summoned to a corner of the cavernous Studio Two to recreate an iconic sound made 47 years ago by another quartet: the Beatles.

On instructions, the lucky group is directed to three pianos—Steinway and Challen uprights, and a Steinway concert grand—and place their hands on keys marked with colored tape. On cue, they strike the chord, let it sustain as long as possible, and indulge in a rare act of rock 'n' roll tourism: playing the thundering finale of "A Day in the Life" in the same room, using the same instruments as the Beatles did in 1967.

Exclusive music experiences are hard to come by in a world crowded with rock-fantasy camps and backstage ticket packages. Some other famous locales, such as the Sun and Stax studios in Memphis, Tenn., have long courted the tourist trade with museums and memorabilia.

Yet Abbey Road has been mostly off limits. It is in London's placid St. John's Wood, where neighbors good-naturedly tolerate a stream of global tourists, even as they slow traffic by recreating the famous Abbey Road album cover in the crosswalk out front. The studio remains closed to the public, however: It is still a working business, used mostly now to record film scores and superstar albums. 

But for two weekends each year since 2012, Abbey Road has offered a rarity: public access to the famed Studio Two, where the Beatles recorded the vast majority of their catalog. The events are built around a lecture by Brian Kehew and Kevin Ryan, authors of "Recording the Beatles," an obsessive forensic breakdown of how the band worked. This year, Ken Scott, an engineer who worked with the Beatles on "The White Album" and other classics, joined Messrs. Kehew and Ryan.

The £85 ($144) price would buy a modest seat for Paul McCartney's U.S. tour this summer. But it is a sought-after ticket and a unique experience. When a projected diagram shows how the Beatles arranged their gear for their earliest sessions, visitors may realize they are sitting about where the band recorded the screaming vocals of "Twist and Shout" in 1963.

The studio's owner, Universal Music Group, took custody in 2012 with its $1.9 billion acquisition of EMI Group Ltd.'s recorded music unit. Faced with the choice between cashing in on Abbey Road's past or securing its musical future, Universal is opting for the latter.

David Joseph, chairman and chief executive of Universal Music U.K., said in an interview that Universal is seeking permission from planning authorities for an ambitious expansion and upgrade of the facility, which includes three studios. If it secures approvals, Universal will add two new state-of-the-art studios aimed at new rock, pop and urban artists; a "retro" studio stocked with vintage Abbey Road gear for old-school analog projects; and gear to make recordings for a new Dolby "immersive" cinema sound system.

Previous owners considered developing a tourist destination or even selling the property. "It's a world-famous brand in a residential area with half a million people stopping by a year," Mr. Joseph said. But Universal decided "it's a place where we still need to record classic albums," he added. He wants to ensure that a "new 17-year-old's guitar band gets access to Abbey Road," he said.

Still, there are other plans to exploit Abbey Road's association with amazing audio. A yellow Mini Cooper parked in front of the studio last weekend featured the prototype for an Abbey Road-branded sound system, a joint venture with Panasonic Automotive Systems. Mr. Joseph said the company is talking with computer, tablet and phone manufacturers, exploring a high-quality Abbey Road streaming music service.

The public lectures, which are reprised this weekend, explain why the place is so historically important. Messrs. Ryan and Kehew demonstrated how a plaintive, unadorned John Lennon vocal for "Lucy in the Sky with Diamonds" was tricked up with an effect invented at the studio by EMI engineers.

Some of the magic was inadvertent. Mr. Scott described a session in which the group tried and failed to nail a passage of "Glass Onion." After his account of each take, the studio filled with the Beatles' voices from the session, lamenting the miscues. Finally, the band got it right—and Mr. Scott got it wrong by starting the tape machine at the wrong time. But Mr. Lennon embraced the error and let it stand, giving the finished track the kind of quirk listeners have always assumed was carefully planned.

"It had nothing to do with The Beatles," Mr. Scott explained. "It was my cock-up."