It’s Eric Clapton -- at an after-hours club

It doesn’t take much to send Eric Clapton scurrying back to the blues, the spiritual wellspring of most of his music over the decades. His latest album is a set of songs by Robert Johnson, and his concert at the Hollywood Bowl on Monday was loaded with blues.

He offered clues even before the first note. Instead of the sharp suit he’s worn in recent years, the singer-guitarist was dressed as if for sound check, in rumpled jeans and a plain shirt.

And his band was slightly reconfigured, with Texas guitarist Doyle Brahmall II and veteran British blues-rock keyboardist Chris Stainton in for more versatile, pop-leaning musicians Andy Fairweather Low and David Sancious, respectively.

All this made for a radical departure from his last tour in 2001, which showcased some of the range he’s managed to stake out by bringing blues voicings and moods to a broader pop and rock context.

In narrowing his focus this time, Clapton elevated the sense of commitment in his playing at the expense of variety and entertainment. He didn’t even do his VH1-generation breakthrough ballad “Tears in Heaven,” and renditions of “Badge” and “Layla” were perfunctory.

Although this emphasis put him in his musical comfort zone, it didn’t appreciably loosen him up as a performer. He remains one of the stiffest stage figures in popular music, his passion for playing bumping head-on with the impression that he’d rather be doing it in an after-hours dive or alone in his room than in front of 18,000 people.

Whatever he had, he saved it all for the solos. The concert featured one showcase instrumental after another, a series of displays that delighted the fans whose reverence is based on his guitar heroism.

Even here, though, the preponderance of blues -- especially slow blues -- resulted in a sense of repetition.

More than ever, Clapton is true to his era of origin, the 1960s, when the discovery of new musical horizons and the emergence of unprecedented virtuosity replaced rock ‘n’ roll’s fun, showmanship and personality.

That’s why the encore segment was so bracing, with the evening’s opening act, the fiery blues-gospel steel guitarist Robert Randolph, sitting in and giving the show a galvanizing jolt of energy.

Now that’s how you get your mojo workin’.