You can experience this joy for yourself if you download Kills, the new mixtape from Swedish echophiles jj. It’s free, so nobody can tell you it’s not worth a listen. And it is!: not for breaking much ground, not for mind-blowing content, but sheer intrigue.

This form of “mixtape” is easier to experience than describe: it’s a collection of songs and tidbits that jj liked so much they felt compelled to sing all over them. Samples drift in and out of clarity like they’re being wrestled underwater, which neatly fits Elin Kastlander’s swathey vocals on ‘Still’: “kill so many songs you’d think I have a hitlist”. The semantics could swing either way – either they think they’re, like, nailing these songs, or slowly choking them to death. The actual result is somewhere in the middle.

Well, nothing’s being done with these scraps of M.I.A., Dre, Jay-Z and Kanye West that hasn’t been done before. To clarify: nothing much is being done with them at all. On ‘Kill You’ the unmistakable pinched-guitar riff of ‘Paper Planes’ wanders into earshot and away, laid over with some synth strings and Kastlander’s vaguely tough-guy lyrics, a pastiche of the stolen and the invented: “I wanna die / so I get high / I blame it all on me / ’cause I wanted to do it”. Most vocals are autotuned for that polygonal feel; it works best in the trance-pop soup of ‘Die Tonight’, which opens by noodling around a Robyn lyric and ends on a “fuck all you hoes” sentiment. It’s more about layering and improvising on a theme than remixing, or cultural flooding like Girl Talk: being a “mixtape” is core to Kills’ identity, and the lens through which it’s most impressive. Seen as “new” jj songs, these are obviously derivative, but as a mixtape it’s a nice experiment. Instead of just the order, jj are able to play with the spaces in between (and inside) their chosen songs, and to force the common elements of tinny drums and breathy vocals upon them.

The latter half of Kills is less catchy, but might be more palatable for some; it just feels more respectful. To elaborate: the lyrics of the opening tracks just seem to rely on the novelty of having a white girl swear like a sailor and talk about the drugs and the bitches etc in milkier tones than the spawn of Enya – not that swearing/drugs/bitches are foreign concepts to white girls, but it’s the juxtaposition with those samples, almost entirely taken from rap, hip-hop and R’n’B music, which makes it all begin to feel like a tired joke. (See also: many Radio 1 Live Lounge sessions, or 90% of ukulele players with youtube accounts – both heavily rely on the humour apparently inherent in tweeing all over gangsta rap.) But with ‘Angels’ and ‘Boom’ we get some genuinely good songs, with structures and big and capable beats that justify jj’s recent tour with The xx even better than their band-name aesthetics.

So while it’s hit and miss, Kills is inarguably absorbing – drawing you in just as a mixtape should, with a mixture of dread and excitement for each next track, and hopefully yielding some surprises. For example: on ‘Believe’, there’s a long sample of an interview with Nicki Minaj over a real cutesy, repetitive R’n’B hook, and she’s talking about Lil Kim, and it really, really starts to feel like a parallel universe version of Iggy Pop’s bit in Mogwai’s ‘Punk Rock’. No? Just me, then.