It's a force of habit now that before hearing something you try and find out about it, eliminate mystery for the security of prejudice. I'm gratified that most of what I've read from the two genii involved here, Dilated People's verbal tactician Evidence and underground legend producer Alchemist is totally nebulous, pisstakey, and unrevealing. According to Alch, Lord Steppington is "very British-inspired so it's a lot of tea drinking, scones, and Benny Hill episodes. Lord Steppington is just a caviar eating, lord of the underground of rap that looks down on the rest of the underground. We're just full of caviar, basically." I can't hear any of that myself, but can see some sense in another interview in which it's clear that Alch's ambitions seem provocative, antagonistic: "I want to anger people who expect something that I've done in the past, because I'm just that type. I'll probably destroy something before I build it. I'm just a jerk like that. So that's my goal, just to make people upset for a brief moment." This seems closer to the truth of the beautifully packaged 'Lord Steppington' (feel the velvet), hip hop's first masterpiece of 2014, an angry, fucked up, freaky slab of delight that just might be the most consistently compelling thing either protagonist have given us in the past decade.

Partly of course, with Alchemist involved, it's down to the beats. He was a busy man in 2013, producing brilliant beats for everyone from ol' Mobb Deep buddy Prodigy, to Durag Dynasty, Boldy James, Gangrene, Action Bronson, Roc Marciano – what Alchemist brings to his productions, like all really great producers, is both dependability and intrigue, although his soundworld is predictable inasmuch as you know the beats are gonna be rocksolid and the loops twisted as fuck, always still startling exactly what he swirls into his maelstroms, how far out he's gonna get, how far in his transmissions end up being lodged and linger. Lord Steppington is arguably his finest since Domo Genesis' No Fools mixtape, certainly an album on which his production is more freewheeling than it has been in a while, noisier, angrier, determined.

This abrasive beauty, almost-psychedelic in intensity and reach, is matched by Alch & Evidence's rhymes, possessed of a febrile incisiveness that you sense is always trying to match and suit the strange sounds unfolding around and behind them. This is an album about class and status and being at the shitty end of the stick, the fantasies of revenge, proud scumminess and inchoate loathing coming thick and fast, thrilling in their force and fury. Opener 'More Wins' nails the onward trajectory, a gritty lushness, a pounding at the temples, a heaviness to the intuitive focus on the keynote of each track, the loop that unhinges everything from just being a straight-ahead blast.

'Dr Kimble' and 'Byron G' keep the sound pressurised, dropping on your head like heavy rocks, bass always thought about and moving and changing in a way too much hip hop can't be bothered to enact anymore. The entirety of 'Legendary Mesh' finds itself surfing on a belching eternally-cresting wave of sludgy fuzzed-up lo-end that winds up taking over, 'No Hesitation' ft. Styles P is the first really startling highlight, a beautifully executed collage of delayed/reversed strings and slomo bass over which Ev and P flip past and future, muse on the irrelevance of edigree, the unshakeability of history. 'Swimteam Rastas' is one of the strangest slabs of musique concrète hip hop you've heard since Show & AG were in their prime, so dissonant, so unstoppable it's as if the Brooklyn Bridge has been rerouted into your living room and through your skull – then the chorus drops and it's all heavenly 70s soul, showstopping flamboyance that eventually gets sucked back into the madness of the verse in crushing waves of noise and decay.

'Mom's In The Garage' sees Action Bronson ripping new holes in your brainpan over a welter of (yup) British movie samples, 'See The Rich Man Play' explicitly nails what the album's only been hinting at up to that point, Roc Marciano spilling out fantastic rhymes about 'feeling grim', poverty, yearning, dreams, the other half and how they live, our half and how they die, those days when only 'playing Miles Davis 'Bitches Brew' seems to soothe you, the haunting sounds of fruit-machine payouts and alarms accompanying your penniless return to the pavement.

'Banging Sound' mashes 60s psyche-pop with rotational post-punk arrhythmia in a way even Edan couldn't dream of but it's 'Tomorrow' which features Rakka Iriscience and Blu that'll truly see you out the other side of 'Lord Steppington' with your mindseye washed clean in a bath of mescaline – a track so lassitudinal it nearly grinds to a halt, but with gorgeous flickering detail over its almost-dub undertow, redolent of nothing so much as some divine collision 'tween Bill Withers' 'Railroad Man' and Erick Sermon's 'Bomdigi'. 'Lord Steppington', in ranging so far and wide sonically, will doubtless be criticised as uncohesive, rambling – it's precisely that tone of excess, when set against the focus of its lyrical attack, that makes it so damn compelling and so replayably rewarding. Vanish into Lord Steppington's pocket and enjoy the ride, the sights, the sounds, the smells, the strangeness. Making less and less sense the more contact you have. Addictive aggravation.