Collaborations are funny beasts to deal with. They happen so often in the world of leftfield music that sometimes you're left with the assumption that everyone just bandies about with a 'why the fuck not?' attitude? I mean, Andrew W.K. must have played with just about everyone by now. I wouldn't be surprised if he had a delicatessen-style ticketing system organising his next couple of releases.

I'd speculate though, on a serious note, that the act of artistic collaboration in underground scenes has more than just a 'sure, let's kick 'em out' reasoning behind it. Collaboration broadens networks, builds relationships (which in DIY circles are more important than haemoglobin) and allows musicians and creatives to broaden their spectrum – and maybe leave their comfort zones a little.

All this talk of collaboration neatly leads me to get to the point – Foreign Body by Mirroring. Mirroring is Liz Harris (more commonly known as Grouper) and Jesy Fortino (more commonly known as Tiny Vipers). Both are natives of the Pacific NorthWest (Harris, Portland – Fortino, Seattle), and you can hear this in the timbre of both. Grouper's haze of melancholy spreads and soaks like her perma-soggy city, and Tiny Vipers' usually brittle acoustic arrangements hint at a similarly overcast landscape.

What's interesting is the way Foreign Body starts off. The disparate level of input between opener 'Fell Sound' and second track 'Silent From Above' is obvious, and it seems Harris and Fortino are fleshing out their involvement with the project, sizing each other up and seeing how this is going to work out. 'Fell Sound' is a typical Grouper mist of drenched, floating ambience that supports her vocals, cloud-like. 'Silent From Above', however, showcases Fortino's place as an alt-folk chanteuse, less edgy than Cat Power and not as quirky as Joanna Newsom, but carrying such weight with her voice that you wonder how such pain could be absorbed, let alone articulated.

This is followed by 'Cliffs', which mutates between the two artists, beginning as it does with scratchily picked guitar, which in turn is enveloped by static, which is in turn punctured by guitar, which…You get the idea. It's the 'we're figuring this shit out' section of the record, and it makes for a wonderful transition – but also the record's weakest moment.

'Drowning The Call' is where everything starts to click. Everything previous was still Mirroring, but this is what Mirroring actually is. The sound is met and made and whole as guitar and chiming organ loops swim together in a sea of washing ambience.

'Mine', the standout song on the album, builds on this with more urgency and immediacy; it's nine minutes of building drones and delayed guitar egged on by vocals much stronger and more assured than before, finally losing itself to two minutes of static drones and tones that eclipse the beauty and collapse heroically. This paves the way for 'Mirror of our Sleeping', a somber valediction to the whole affair. A goodnight.

But for all that dissection of input, the most beautiful thing about Foreign Body is that it is more than the sum of its parts – it is standalone and whole. Of course, it's fun to play 'who wrote what part', and if you know of either artists' previous work it's not particularly hard to see which input comes from where, but to do that is to really miss what makes this such a great work of art. What does make it such a great work of art is that through a meeting of two talents, one complete whole has come from it – work that stands alone to be judged and accepted as the singular entity it is. 'Foreign Body' is a wonderful album that charms and endears and soothes, and in no way is the brilliance of either musician compromised – which is pretty much the highest praise it can be given.