Red Hot Chili Peppers, O2, London Chic, Forum, London

The Eagles of funk metal haven't noticed that their sound – and their puerile jokes – stopped being entertaining years ago

The phrase "sports metal" now resides in the Rock Terminology Graveyard. It's a shame it never caught on, because it perfectly describes the phenomenon of which Red Hot Chili Peppers were the shock troops and pathfinders.

RHCP, alas, are anything but a footnote in musical history. In the late 1980s, their very physical presence ran counter to alternative sensibilities. Their rude health, their big North American mouths with their jutting Greg Rusedski jaws and equine teeth spoke of people brought up on calcium and sunlight, not misery and drizzle. And things were never the same again: muscle and tattoos were where it was at, and semi-naked cavemen strutting about with elasticated socks on their members.

And this is where it's brought us: thousands upon thousands of music-agnostic drones shuffling into the Dome for a battery farm gigging experience, undergoing double bag searches and metal detectors and paying £5.45 for a pint of cider, all for the privilege of squinting at 50-year-old men in white vest tops doing bunny hops and pulling head-wobbling funk faces at one another.

Strangers to dignity, the Chili Peppers' main message is still priapic rather than profound. "Hey, who wants to see my penis?" offers bassist Flea, on more than one occasion, until even he has to concede: "It's not that good a joke to begin with." Much the same could be said for his band.

Oh, they've made the odd decent record over the years. Not so much the asinine assassination of Stevie Wonder's "Higher Ground", or the daft thrash of "Right on Time", as the late period Californian melancholia represented tonight by the likes of "Otherside" and "Hard to Concentrate": the material on which they became, effectively, The Eagles of funk-metal. And it's hard to argue with "Give It Away", tonight's finale and the moment on which their thumping, thug-ugly thing attained an undeniable might, and on which Chad Smith – a drummer who is louder than he is good – comes into his own.

Their musicianship leaves me cold. As Flea breaks off from blowing a stand-mounted oboe to play a show-off bass solo, it occurs to me that his real career highlight, playing a German nihilist in The Big Lebowski, is a role in which he doesn't play a note.

The departure of guitarist John Frusciante has hit RHCP harder than they admit. "If ever I'm feeling a little off," Anthony Kiedis tells us in praise of replacement Josh Klinghoffer. "I like to listen to Josh play guitar." But the new boy couldn't save the latest album from being a turkey. Between songs, Klinghoffer doodles a snatch of "Lola" by The Kinks, which rams home that it'll be a cold day in Beverly Hills before RHCP write a song with similar subtlety and wit.

Only a handful of humans can claim to have reshaped pop for the better, and Nile Rodgers is one. This year, we almost lost him. The guitar hero and production genius announced in January that he had an aggressive form of cancer, and has spent much of 2011 detailing his experiences in a blog, Walking on Planet C.

Now in recovery, he's fronting an incarnation of Chic bereft of his songwriting partner and bassist Bernard Edwards (who died 15 years ago) and drumming powerhouse Tony Thompson (who followed in 2003), but he's visibly loving it none the less.

In dreadlocks and an ice-white suit, the great man speaks of "coming through the fire" before leading his phenomenal backing band through one of the outstanding gigs of the year. In his hilarious and eye-opening autobiography Le Freak, Rodgers explains how Chic aimed to bring the class and panache of Roxy Music to black music, creating a positive feedback loop wherein the Eighties generation – the ABCs and Durans – tried to emulate Chic. They also, of course, gave hip-hop its groove when Sugarhill Gang sampled "Good Times" on "Rapper's Delight", as Rodgers reminds us by mashing those two tracks together.

It's a set that ventures beyond the Chic hits and the usual Diana Ross/Sister Sledge medley into other Rodgers productions, including Bowie's "Let's Dance", Madonna's "Like a Virgin" and, to my utter delight, Sheila & B Devotion's sublime "Spacer".

There's something thrilling about hearing the church-bell cascades of "I Want Your Love" or the disco rapture of "Thinking of You" while watching the hands that created them chopping out the licks in that upturned-palm strum. Aurora borealis seems to spark from his fingertips.

Tonight was, Nile says, all the more special because "I didn't think I was gonna be around". One way or another, Nile Rodgers will always be around.

Next Week:

Simon sees sofa-lipped Hollywood sadcore heroine Lana Del Rey

Rock Choice

An insanely stellar line-up including Lady Gaga, Coldplay, Elbow, JLS, Jessie J, Hugh Laurie, Snow Patrol, Kelly Rowland, Andrea Bocelli and Michael Bublé plays the BBC Children In Need Rocks concert at Manchester's MEN Arena (Thu), while The Cure perform their first three albums in an epic set at London's Royal Albert Hall (Tue).