Kylie Minogue, SECC, Glasgow <br/> Cee-Lo Green, Shepherds Bush Empire, London

Kylie, I'm so sorry. It's not you, it's me. Oh, I know you're physically incapable of making an actively bad record. Even with a relatively lacklustre lead single in "All the Lovers", your latest album Aphrodite was still a solid four out of five, but it suffers by comparison with the career-best X lurking large in your rear-view mirror.

Have I met someone else? Well, kinda. She's younger, more outrageous; she wears dresses made out of meat, and she's released at least one leonine roar of an immortal über-pop monster that matches "Can't Get You Out of My Head" for unshiftable earworm power.

Yes, on paper, I still recognise that you're a pop genius (albeit the collaborative kind). But I feel like I've reviewed you in Glasgow's SECC at least twice already in my Groundhog Life. What with one thing and another, for the first time in 20 years I'm just not in a very Kylie Minogue mood.

Then I see you flying overhead on the back of a white-winged, black-skinned avatar of Pygar from Barbarella, alighting on a podium with one tiny, gold-heeled boot, flashing that toothy smile, and not missing a beat. Then I see you riding round the rhomboid stage on a gilded chariot like Boudicca or – in the week that Queen Liz died, I prefer to think this – Cleopatra for "I Believe in You". And, once again, I do believe in you.

Oh, come on, we all knew a happy ending was coming, right? With a Graeco-Roman spectacular like the Aphrodite: Les Folies tour, resistance is futile. It's Busby Berkeley meets Ben Hur, right down to the obligatory muscle boys on trapezes feeling themselves up between the Doric columns.

It sees the singer venturing further away from Greatest Hits than any show since the Indie Kylie days, although with "Spinning Around", "What Do I Have to Do?", "Confide in Me" and "Better the Devil You Know" scattered like pearls on velvet, there are still more than enough crowd-pleasers. Even the Aphrodite songs are sounding iridescent in context: "Get Outta My Way" is a superior slice of disco euphoria, and "Everything is Beautiful" is a classy bit of poised electro-pop too.

The difference is an increased willingness to take risks (a rocked-up, metallic "Can't Get You Out of My Head"), embrace the arty (using Saint-Saëns' Carnival of the Animals as her walk-on music) and the relatively obscure (a show-stopping, sat-on-the-staircase rendition of Prefab Sprout's "If You Don't Love Me").

That voice – tasting of peppermints, peaches and helium – has never been stronger: she audaciously outdoes La Lennox on a fantastic version of "There Must Be an Angel" in her own backyard. But the absolute killer comes when Kylie takes a break from the butt-pumping beats for a dusky, sultry jazz version of "Slow", complete with Moulin Rouge fan-dancers sprawled on a tilted turntable with the singer as the spindle. It's one of the set pieces of this or any other year.

Kylie, if we – the pop public – have been taking you for granted of late, we owe you a collective apology. On a night like this, the only word is wow.

Maybe I'm just too demanding, but I do like my soul men to make a bit of an effort. A sharp suit, tradition demands, ought to be the bare minimum. Cee-Lo Green thinks it's fine to saunter around the Shepherds Bush Empire stage in a black T-shirt and baggy trousers, looking for all the world as though he's come from a jog (which, let's face it, is less than likely). Only the bling bling crucifix which is probably worth more than your house, gives the game away that this man is, in any way, a star.

He's a strange case, Cee-Lo. After his first successful act Goodie Mob disintegrated, he was doing OK, his career ticking over as a journeyman soul singer, picking up guest spots with Common, Outkast and P Diddy.

Then Danger Mouse came on the scene, picked him up as the face of Gnarls Barkley, and one international runaway hit with "Crazy" later, he's undergone an unlikely late career flowering as a Luther Vandross/ Alexander O'Neal for the 21st century, winning Brits in his own right on the back of novelty hate-song "Fuck You" (or, to use the Robocop-style radio version, "Forget You"). And now he's got our attention, he doesn't seem to know what to do with it. There's no stage set tonight, no fancy lights, not even a backdrop. Only the all-female backing band hints at any conceptual or visual awareness.

Occasionally, when he can be bothered, he'll use his peculiar physique – like a scaled-up dwarf – for comedy purposes, or raise his chubby tattooed arms into overhead handclaps, making his bingo wings shudder in time to the beat. There's some cursory, rehearsed banter: he precedes "Fuck You" with a mock-tearful tale about "coming out of a fucked-up relationship". And that's it.

I can see why people like, or at least don't dislike, Cee-Lo. He chimes with a certain generation's alternative mindset (with Gnarls Barkley's cover of Violent Femmes' "Gone Daddy Gone" and a snatch of The Clash's "Rock the Casbah"). He has a serviceable voice, nothing more. Pleasant in tone but limited in range, and applied to mostly boring, monotonous material.

Next Week

Simon finds out if the reunion of Mick Jones and Don Letts is BAD or just bad.

Rock Choice

Fans of vintage Afro-Cuban sounds should catch Orquesta Buena Vista Social Club, right, while they still can, at Southend Cliffs Pavilion (tonight); Birmingham Symphony Hall (Tue); Cheltenham Town Hall (Wed), Cardiff St David's Hall (Thu); Bristol Colston Hall (Sat and beyond). At London's Electric Ballroom, hype monkeys The Vaccines play their biggest headline show (Thu).