What have Tony Di Blasi and Robbie Chater been doing for 16 years since the last, the first, Avalanches album? Apart from losing founding member Darren Seltmann around halfway through their "hiatus" that is. Getting more and more obsessed, for one, you suspect. Listening to possibly every sound made on a recorded disc of any sort in the past 90 years, for another. Stitching together some – and by some I mean a few thousand possibly – of those sounds into a kaleidoscopic collection. (Actually, it should really say krazy kaleidoscopic kollection because there is, at times, a kind of bug-eyed, 'hey we're all having a w-i-l-d time, half-price-for-you, get-em-while-they're-hot', underlay to the soundscape of Wildflower. More of that soon.) And once stitched together, unstitching, repositioning, restitching and discovering that there was one more sample which could be added. Maybe two. Three at the very most. OK, four but that's the final offer. Listening to this 21-track album on headphones, which I did exclusively until my head threatened to explode around the fifth or sixth listen, is both sensible and fraught.

Sensible, because at some point you must listen in full detail, to grasp the complexity of the sounds and their interaction. To hear that, yes, at some point in the past someone thought to record a primary school choir singing the Beatles' Come Together and that at some point more recently someone else thought to insert that into a mix of whirling circus parade, classical strings, crunching vegetables (a la the Beach Boys on Smile, not the first or last Beach Boys reference on the album) and rapper Biz Markie. When a voice crashes into a drum and rolls seamlessly into a jazz pattern that turns out to be more fractured than framed, you find yourself agog and pleased. Likewise if you pick up the Bee Gees elements across several tracks or if what you suspect could be Doobie Brothers, actually is. When a parping tuba and whistle make the merging of a calypso, a carnival and drooping-drawers, mildly agitated rap – which can rhyme "Farrakhan" with "Frank Sinatra man" – comfortably odd feels almost normal. As does the blissful post-hippie vocal group harmonising, which can sit against trilling flutes or clattering drums, or a man intoning about "the fulfilment of a 10th grade prophesy", while the sounds around him have you certain you can smell the dope inhaled by some producer in a rural French studio. And when somehow A Few Of My Favorite Things appears in that Frank Sinatra-referencing track, like the maiden aunt who's just heard you're having a party while your parents are away and loves the idea of talking with those lovely young people ... well, let's say agog is the least of it.

Di Blasi and Chater have long gone past being the clever bastards' bastard sons of Paul's Boutique, the 1989 Beastie Boys album which predicted the potential for the Avalanches' Since I Left You in 2000 and created the legal framework now necessary for securing the rights to all those sounds. And therefore the album, which made the final stages of Since I Left You (and you would assume all the stages of Wildflower) laborious, finicky and precarious. However, being the clever bastards is still at the core of their being. That's mostly for the better. This attention to detail suggests some brilliant ideas allowed to flourish and flourish at their own time, with the aptness of some of the weirdest juxtapositions of sounds and samples evident in repetition and rewarding their efforts to make everything here bigger, bolder than last time. Clever too, at least in one way, was the decision to make this essentially one long piece of music. With no breaks between tracks but instead samples tiding you over or bleeding into the beginning of whatever comes next, it's not only advisable to listen in one go but makes downloading individual tracks rather than the album seem shortsighted. But also occasionally that cleverness is for the worse, or the fraught. This amount of detail is overwhelming at close quarters after a while: the chance to breathe out, clear out the ear-and-brain channels and prepare to breathe in the next bit, is taken away from you by the non-stop approach.

In the midst of those uninterrupted sessions I was starting to believe that while abundant in sounds and shapes, rhythms and surprises, the album was far too light on for actual songs. You know, things that hang together with an internal golden logic not an external gilt-by-association. Stepping back a bit – literally, putting the headphones down and stepping back from the speakers – allows not just air but some clarity to emerge, not least that that though Live a Lifetime Love feels messy, its lack of cohesion exposed with separation from the rest of the album's waves of sounds, it turns out to be a rarity. The album-closing Saturday Night Inside Out cruises you out of the album with something approaching elegance and Because I'm Me, with its '70s soul funk smoothness and relatively modest sample bag, which effectively opens the album – after the throat-clearing, 15-second prep of The Leaves Were Falling – feels whole, not fragmented. Subways,a bit later stretches that soul funk more towards disco funk but its moves are more on the groove and you can see this being a killer remix down the line. Elsewhere, the floating away on a slippery electronic bed that is Colours, and Stepkids (sounding not a million miles from the band Step Kids actually), which in early goes were more wobbly interregnums than stand-alone numbers, shows their connections between Beach Boys or slacker rock and electronica are not just viable but enjoyable.

The takeaway then from an album 16 years in the making, 21 tracks in the delivery and seemingly much longer than its 59 minutes and 23 seconds? Give it time. Give it, and especially you, space. Do that and you might well give in to an often nutty and just as often exhilarating trip. Wildflower is available to buy on July 8 but is streamed on Apple Music from 8am, July 1. Read Chris Johnston's inside look at the making of Wildflowers in Spectrum, July 2.