Two cult singers on the same bill. A stirring prospect in itself, but last night they were both also at watersheds in their careers. The headliner, Ron Sexsmith, was looking to cultivate a more mainstream audience. He’s had his moments over the years, such as when he was covered by Chris Martin, Rod Stewart and Curtis Stigers. But last night he seemed to want the fans to have another look at him. On one song he styled himself as a “late bloomer”, but he didn’t need to convince this crowd.

N-Dubz's music is throwaway post-grime cheese-pop aimed at fans aged between 10 and 20, max. I've been writing a rearguard action for electronic pop in the pompously self-assured court of rock for more than a decade so I arrived at the Brighton Centre ready to sponge it up.

“I thought I was creating metaphysical history by running Creation,” says the label’s Alan McGee in Upside Down. Seconds later the meat-and-potatoes rock of Oasis blasts from the soundtrack. The drug-assisted disconnect between such lofty aspiration and the grounded music of Oasis was never going to be bridged. Even by the man billed as “the president of pop”.

In the lager-carpeted sweat box that is the KCL student union it was hard to fault The Mummers. There are some concerts where band and audience seem so lost in a private world that you can almost forget that the humdrum, everyday world even exists. Last night was one. It was no surprise that Raissa Khan-Panni and her gang were there to transport us. What did come as a revelation, however, was just how big it sounded. The musicianship was just the half of it, though.

“I thought I was creating metaphysical history by running Creation” says the label’s Alan McGee in Upside Down. Seconds later the meat-and-potatoes rock of Oasis blasts from the soundtrack. The drug-assisted disconnect between such lofty aspiration and the grounded music of Oasis was never going to be bridged. Even by the man billed as “the president of pop”.

The downside of this job is that because new CDs are dropping through the letterbox every day, a lot of stuff inevitably gets consigned to the archives and forgotten about, when it really shouldn’t be. So when I heard that The Mexican Institute of Sound (aka Mexico City’s Camilo Lara) was rather belatedly playing live in London for the first time (his last album was released two years ago), it was an excuse to reacquaint myself with his recorded works to see if they were as good as they seemed at the time. The good news is that they are, but the less good news is that this concert didn’t really do them justice.

This was one of the funkiest shows I’ve seen for a long while; perhaps even since Prince’s peerlessly funky residence at the same venue in 2007 (though nowhere near as brilliant). There came a moment, on "Deeper Underground", when everything just clicked – the bassist and the drummer were locked in a deep groove, the guitarist was doing his precisely controlled chopping thing, the percussionist was rattling his timbales, the brass section popped and squirted, the backing singers shimmied, and singer Jay Kay himself did that weird dance, almost nerdy: glide-jerk, glide-jerk. Looking around the arena, I saw a sea of blonde highlights and jiggling bodies; the place was seething.

As her black robe swirled around a black leotard, Lykke Li became the anti-Stevie Nicks. Instead of conjuring the mellow California feeling, she sang “sadness is a blessing”. Yet this Swede’s pop is as uplifting, as transporting as any good vibe merchant. More so. Last night’s show transfixed with its Bo Diddley beats, gospel choruses and wheezy garage rock organ. Rather than being a retro futurist, Lykke Li takes from the past and recasts it to fit her vision of what affecting pop ought to be.

Bear with me while, like supergroomed rising star Miloš Karadaglić retuning his guitar to a mellower vein, I adjust my concert-hall vocab and describe this as a no-gimmicks sell-out gig underground with young musicians from the London Philharmonic’s Foyle Future Firsts scheme presenting two varied sets and Karadaglić headlining. And now I’ll just revert to old habits and declare the meat to be a slice of Classicism chromatically spiced (Mozart) and a 20th-century maverick pushing Neo-Baroque into near-atonality (Stravinsky), our top guitarist serenading by way of late-night coda. All this to listen to with the intent of a seasoned concertgoer or to doze to with drink in hand, as you please.

Not that some of the sweet juve players were entirely cool with it. When you've always kept your audience at arm's length in a recital space, it can't be easy to find folk at tables right under your nose texting and quaffing. But the point is that this was good practice even for the less seasoned meeters-and-greeters, since the set-up had to include introductions varying from the read-out high-falutin programme note your average newcomer to classical cabaret just wouldn't get to a bluff line in curt preface: of the Poulenc Sonata for trumpet, trombone and horn, we were told, "One critic said that this was 18th-century music with wrong notes. They're not wrong notes, and we hope you like it."

I did, and I also liked bassoonist Laura Vincent's personable introduction to the two movements of Stravinsky's Septet, toughest numbers on the programme for which there was no avoiding a bit of explanation about a passacaglia and a gigue verging on atonality; she even got away with the "Stravinsky was the Madonna of his time" line. And James Turnbull is a natural, brimming with genuine enthusiasm for one of the best oboe pieces not actually written for oboe, as he put it: "Nightclub 1960" from Piazzolla's History of the Tango, transcribed from the flute-and-guitar original. He delivered it with panache alongside subtle harpist Elizabeth McNulty, whose earlier glissandi in the Debussy Trio had showered stardust over late, lamented Humphrey Lyttleton's stuffy but ever-atmospheric venue (reprieved, I'm delighted to hear, from imminent execution).

The "sets" were well thought out in chunks of 25 minutes each, the first sandwiching the Debussy and a movement from the Ravel duo-sonata - stunningly executed by violinist Emily Dellit and cellist Arturo Serna - between Stravinsky's trio arrangement of numbers from The Soldier's Tale, and the Poulenc, showcasing a nice line in vibrato-ed trumpet song from Ellie Lovegrove. Good to know, too, that laughing at musical humour is not the prerogative of all-too-knowing Wigmore old-timers. The slow movement from Mozart's Quintet for piano and winds was the stilling heart of the second sequence, nicely set up by a Julian Anderson miniature and bringing together seven of the 14 players (most of them pictured above) sharing the platform for the later Stravinsky. Some of the groups need to loosen up and just enjoy the freedom such a space can give them, but again, it's all good practice, and drew the listeners in even as the old air con chuntered and the bar flies chattered.

Total silence, on the other hand, greeted the star turn. Fair enough, 28-year-old Karadaglić has a new CD to flog, his first for Deutsche Grammophon. Surely conscious of the matinee-idol looks which are going to be a selling point, he accounted for himself in a manner both much slicker and at the same time seemingly less sincere than the youngsters. But he was here on the eve of his Wigmore recital to show his artistry, and if the injunction "let's rock" didn't translate into the results, we did have more than a sample of his poetic soul. I'm no doyen of the classical guitar, and the only time I've heard the colours of a full orchestra in it was a year ago, from that absolute master Paco Peña, but there were certainly the shades and freedoms of a fine artist in the Albéniz pieces and the lullaby-esque Tarrega encore he gave us.

Karadaglić makes much of his pride in the Montenegran motherland, and finds there's no place like home every time he plays Carlo Domeniconi's variations on a Turkish song, Koyunbaba. Well, it's not great music, even if the tune it reflects upon is of the essence, but this was just what we needed at coming up to 11 o'clock: a late-night meditation that had an air of the improvised about it. Which again is the highest praise, and makes me wonder if real improvisation might not be the next step for relaxed "classical" cabaret nights like this. Bravo to the glammy ladies of Limelight for setting them up and moving them forward; they'll surely run and run.

• Next Limelight event in August features soprano Danielle de Niese
• Karadaglić's next recital is at the Wigmore Hall on 15 April
  
• Further details about the LPO Foyle Future Firsts scheme

Next page: Karadaglić plays part of Albéniz's Asturias