Mavis Staples looks like a boxer on the cover of Live in London: Head down, chin tucked, fists balled in front of her face like she’s about to pop the microphone with a left jab. Odd as it may seem, it’s a fitting pose for a musical heavyweight who is still slugging it out on the road at the age of 79. And who can still knock out audiences night after night with consummate skill and style. For the tale of the tape, go inside this stunning, soulful set recorded over two days in England last summer (including her birthday). Unlike other so-called “heritage acts” resting on their laurels and classics, Staples stays current here, drawing on the critically lauded, award-winning and commercially successful albums she’s made with Jeff Tweedy, M. Ward and others over the past decade — while ignoring gospel chestnuts like Respect Yourself and I’ll Take You There. You won’t notice their absence once you get a load of some of the other memorable moves in her repertoire: Magnificent, magnetic versions of Curtis Mayfield’s Let’s Do It Again, P-Funk’s Can You Get To That, Talking Heads’ Slippery People and deep Staple Singers cuts like What You Gonna Do, We’re Gonna Make It and Touch a Hand. No matter how she bobs and weaves, though, her compact touring band is firmly in her corner all the way, bolstering and boosting her with nimble southern-soul grooves, stinging guitar lines and earthy vocal harmonies. Bottom line: Pound for pound, she still can’t be beat. Here’s hoping she never throws in the towel.