As someone who decided at age 14 that big band kingpin Duke Ellington was the coolest man ever to walk the earth, the Guinness Cork Jazz festival always struck me as the most romantic place on Irish soil. Boasting an alumni that included some of the biggest talents in the genre, Ella Fitzgerald, Oscar Peterson and Dave Brubeck to name but three, it seemed like Ireland's answer to the groove-laying, fingersnapping Meccas of New York and Berlin that I'd read about in history class (what my secondary school curriculum neglected to mention was that while Louis Armstrong was blowing his horn across the pond, the moral guardians of our own Free State were desperately trying to outlaw such paganistic rituals!)

Finally, after a decade of pining, I got my chance to experience the Leeside festival this October, as Cork Jazz celebrated its 34th birthday. But rather than being greeted by a menu of Coltrane and Davis revivals, which, for the record, I would have been perfectly happy with, I was pleasantly surprised to find that the four-day weekender had grown along with me. Taking cues from larger festivals at Montreaux and Montreal, Cork Jazz has expanded its line-up, just as I've expanded my tastes, both of which now take in blues, soul, R&B, rock and hip hop.

Two acts rarely associated with jazz, indie duo Beach House and hip hop luminaries De La Soul top this year's jam-packed bill, while longstanding Irish rockers The Walls and alt. pop darling Cathy Davey appear further down the poster, alongside virtuoso jazzers Tigran Hamasyan and Roy Hargrove. In short, organisers have put on an ample musical spread to keep jazz purists happy, while introducing new blood to the festival at the same time, and, as I discovered in just one night of music, hundreds of musicians are only delighted to fool around under the jazz umbrella.

When I arrive in Cork city on Sunday night, it becomes painfully clear that I've already missed one hell of a party. The ungodly squeal of a trumpet is the first noise to hit me when I get out of the car and the swinging doesn't stop there; there's a bebop trio in my hotel, a funk covers outfit in the pub around the corner, and a brass band performing on the street across the river.

My first port of call is MacCurtain St.'s Everyman Theatre, where game-changing drummer Chris Daddy Dave and his Drumheadz take the stage…just about. An inexplicable train delay in France means that we've been in the building longer than they have, but luckily, this is not the sort of show that demands meticulous planning. An apologetic Dave introduces his band (Isaiah Sharkey on guitar, Kebbi Williams on sax and flute, Jermaine Williams on bass) and invites us to close our eyes and open our minds. There'll be no singalong choruses or hands-in-the-air moments tonight; just pure, unfiltered, improvised groove.

The last time I shared a room with Dave and Sharkey was at a D'Angelo comeback concert in London, when I was treated to one of the most outrageously brilliant shows of my life. Naturally, expectations are high for Dave's own quintet, but the man who counts Adele, Beyoncé, Erykah Badu, Mos Def and Sonny Rollins among his many collaborators needn't worry; the hour-long set is a musical masterclass in outside-the-box thinking.

Aside from a few brief nods to popular songs (elements of 'Amazing Grace' and Hendrix's 'Hey Joe' turn up when I least expect them), an unfamiliar mash of shapeshifting riffs and boundary-pushing melodies make for a truly unpredictable show. Taking in rock, hip hop, acid jazz and R&B, the sound this highly-skilled quartet makes is visceral, immersive, and even jarring. It's as if they've got their instruments hooked up to an audience of voodoo dolls backstage; just when we're getting swept up in one mood, they yank us in another direction. Dave himself is nothing short of a rhythmic Martian, holding down as many contrasting grooves as his hands and feet will afford him, and making full use of his three-stick, four-snare set-up. Hey, they don't call him Daddy for nothing.

Next stop, the Pavilion, where atmospheric electronica maestro Reid and New Jackson, the experimental brainchild of David Kitt and producer Diamond Dagger, get the party started, operating entirely independently of the jazz brief. Seasoned floor-filler Toby Kaar goes a step further, bringing a saxophonist on stage to honk along to his electronic sorcery, and although it's a million miles away from the mind-blowing musicianship we saw in the Everyman, the principle remains the same; why not? The curious horn-blowing adds softness to an otherwise banging set, proving that a good song is a good song, whatever genre you steer in it (thankfully, Kaar's repertoire is full of such numbers).

The music certainly doesn't stop there but, as the wee hours descend, I generally find myself in assorted smoking areas, trading stories with fellow festival-goers. Reports from Gregory Porter, Roy Hargrove and the James Taylor quartet are all ecstatically effusive, so, as I close the door on an eye-opening night of unexpectedly fresh sounds, I resolve that next year, nothing will stop me staying for the whole weekend.