Welcome to String Theory, a new column dedicated to imparting guitar-centric music theory concepts in a practical, useful way that you can readily apply to composing and improvising. Rather than show you a bunch of dry, abstract textbook examples of how chords are built from and live within various scales, I will try to keep things interesting and inspiring by presenting etudes.

The Beatles made EMI’s Abbey Road Studios a household name after they titled their 1969 album for the facility. It was there that they recorded nearly all of their songs, beginning with their first release, 1962’s “Love Me Do.”

Jimmy Page is regarded as one of rock’s greatest guitarists, bandleaders and producers for the incredibly rich canon of music he created with the mighty Led Zeppelin. But not everything produced by the man was as crushingly heavy as Zep favorites like “Whole Lotta Love,” “Heartbreaker,” “Black Dog” and “Rock and Roll.”

The first thing you notice is how close together they are. Led Zeppelin are not scattered around the huge stage of the O2 Arena in London like 100-meter-relay runners awaiting the baton, like most bands at this venue. They are huddled within a few feet of each other in the center of the stage, and they stay that way for most of the two hours or so of Celebration Day, the new movie that captures their one-off return to playing live in December 2007.