2011’s Art & Soul headliner Tower of Power is, improbably, a band best known for its horn section – the T.O.P. horns rank right along with Earth, Wind & Fire’s as one of the greatest of the funk era, if not all time. 

What makes the T.O.P. horns so good isn’t just that they can play, but that they can groove. That’s thanks to T.O.P.’s secret ingredient, which they long ago dubbed “East Bay Grease.” That special sauce is what put the stroke in “Oakland Stroke,” the soul in “Soul Vaccination,” the funk in “You Got to Funkifize,” and made “What is Hip?” hip.

And, among all the other classic acts to have come out of Oakland - from MC Hammer to Too $hort to Tony Tone Toni to Digital Underground - none have had as long a career as T.O.P., who are in their fourth decade of grooviness. In fact, T.O.P. may be the definitive Oakland musical group.

T.O.P. have never been an easy band to pigeonhole. Funkier than an average jazz band, jazzier than an average funk band and with a hearty helping of soulful R&B, its sound bounds across genres. During the group's long career, it's proved its equally adept at soul-stirring ballads, intricate instrumentals and uptempo floor burners. Over the past 40-plus years, T.O.P.’s legacy has influenced several generations of fusion-minded East Bay bands, from the Freaky Executives to the Jazz Mafia.

Birthed in the East Bay bar scene during the mid-‘60s as the Motowns, before morphing into Tower of Power in 1968, it distinguished themselves from all the other bands doing Detroit hits by incorporating lesser-known, and arguably hipper, material into its set list. T.O.P.'s audience has always been multi-faceted as well; formerly managed by the late Bill Graham, it was featured on Winterland and Fillmore Auditorium bills with psychedelic rock acts, among them Jimi Hendrix and Creedence Clearwater Revival.

Personnel-wise, T.O.P. reflected the East Bay’s multiculturalism to a “T”: members were of African, European and Latin descent. In addition to the core personnel of Emilio Castillo, David Garibaldi and Stephen “Doc” Kupka, their current lineup includes Larry Braggs, Rocco Prestia, Roger Smith, Tom Politzer, Adolfo Acosta, Jerry Cortez, and Lee Thorburg. T.O.P.'s famous alumni include saxophonist Lenny Pickett - that’s him blowing on David Bowie’s “Let’s Dance” - keyboardist Chester Thompson and vocalists Lenny Williams, Rufus Miller, Rick Stevens and Tom Bowes.

Besides a catalog of 25 studio and live albums - including classics like East Bay Grease, Bump City, Urban Renewal, Back to Oakland, and In the Slot – the T.O.P. horn section was frequently in-demand for session work. Indeed, the T.O.P. horns have their own discography (!) on the band’s official website. They’ve graced records by Big Brother & the Holding Company, Santana, Betty Davis, Elton John, Little Feat, Rufus featuring Chaka Khan, Graham Central Station, Rod Stewart, Labelle, Sammy Hagar, the Brothers Johnson, the Meters, Peter Frampton, Sergio Mendes, Jefferson Starship, Heart, Eddie Money, Huey Lewis & the News, Molly Hatchet, Smokey Robinson, Rick James, Eurythmics, Linda Ronstadt, Paula Abdul, Bonnie Raitt, John Lee Hooker, Exodus, the B-52’s, Michael Bolton, Public Image Ltd., B.B. King, Terrence Trend D’Arby, Luther Vandross, Phish, Stevie Nicks, Michelle Shocked, Neil Diamond, Tony Toni Tone, Aerosmith, P.Diddy, Joss Stone and Pharaohe Monch – just to name a few. It would be difficult, if not impossible, to name another unit who connect so many disparate artists to each other.

Ask someone what the definitive Tower of Power song is, and a lot of folks would probably say “What Is Hip?,” a tune which somehow maintains its relevance with each passing generation. A few might opt for the classic radio hits “You’re Still a Young Man” or “So Very Hard to Go.” The spirit-cleansing “Soul Vaccination” would surely get a few votes, as would the emotion-wrenching “Don’t Change Horses (in the Middle of a Stream).” And, there’s no denying “Only So Much Oil In the Ground” rings truer today than it ever did.

Yet in my mind, there’s only one answer: “Oakland Stroke.” Released as a B-side of a 7-inch single in 1974, and clocking in at just under two minutes, it’s a fast ’n’ furious funk throwdown with jazzy gracenotes and a bouncy, bumper-car rhythm accentuated by a lyrical refrain: “Glad I found the stroke/ glad I found the Oakland stroke.” It’s one of our city’s undeniable anthems, and one which captures Tower of Power at the top of its game.

Tower of Power appear Sunday, Aug. 21 on Art & Soul's Main Stage. For a complete lineup, click here.