Google Co-Founder Sergey Brin has expressed interest in retiring “in a year or so” to take up the intense study of blues guitar, sources inside Google say. The decision places the company at a crossroads in terms of management succession and a replacement is already being groomed.

Brin has been learning blues guitar from a number of major players including Eric Clapton (who was given $40,000 for a series of three lessons in a Palo Alto park), Keith Richards, and Ralph Macchio.

Those closest to Brin noticed a change in the billionaire as he began toting his electric guitar, a Fender Stratocaster he called “Beulah,” to many staff meetings along with a portable Pignose amp he had attached to his belt. He traded a number of riffs with VP Marissa Mayer at a recent off-site all-hands meeting that Brin called in order to show off how he learned to play Cocaine. Mayer is an accomplished slide player and plays at Mountain View clubs under the stage name “Lady M&M.”

Brin’s decision is an open secret at the company. “He has a little belt clip for the amp. It’s one of those small ones that runs on batteries. It’s on his waist most of the day. That’s where he used to carry his Blackberry,” said one Google exec who asked to remain anonymous. Brin has been known to grab his guitar during meetings and wail out a long, expressive series of notes evoking the concepts of hard-travelin’, women who done him wrong, and the green light being Brin’s baby and the red light being his mind.

He has led a joint Google/NASA project to identify Robert Johnson’s crossroads and has hooked up small, sensitive microphones to Google Self-Driving Cars that prowl the Southern states in order to pick up snippets of “real” music played at fish frys, juke joints, and honky-tonks.

In a leaked memo, Brin explained that the pressures of Google have become too much and that “don’t be evil” doesn’t mean “don’t be soulful.” Brin plants to quit by 2015 and “maybe go down to Baja” to listen to real “people’s music” and then move to Nashville where he will open a small recording studio focused on roots acts.

“I’m going down the road feeling bad,” wrote Brin in the email. “And I ain’t gonna be treated this way.”