When it comes to releasing music, one of the biggest no-nos is to release around Christmas time. In December, the focus of most music blogs and websites are ‘best of the year’ lists and articles citing ‘what to look out for’ the following year. There is a good chance that new music will be overlooked or lost. Hence, it is to be avoided at all costs. But then again, Charli XCX has never really played by the rules.

Charlotte Aitchison (Charli XCX to you and me) signed with Asylum Records when she was 18, and his since proven herself to be one of the most prolific pop songwriters of the past decade. 2013 saw her co-write and sing on Icona Pop’s hit I Love It, and the following year she climbed the pop ranks by co-writing and featuring on Iggy Azalea’s Fancy. Her writing credits extend to material for Rihanna, Gwen Stefani and Selena Gomez.

However, it was her own irresistible single Boom Clap, taken from her 2015 album ‘Sucker’ that truly ratified her pop stature. In a few short years, the Cambridge-born college drop-out had made it. She had the industry in her hands, her ascendance into pop aristocracy was certain.

That said, Charli had other things in mind. She made a sharp left turn and threw the pop rule book out the window. Much to her record label’s apparent perturbation, the singer teamed up with London based alternative producer AG Cook in a quest to find herself. A third album is yet to materialise. Instead, the past 3 years have seen the singer churn out odd mixtapes and collaborative projects with other artists.

Unphased by the fact that the internet was saturated with Christmas songs and ‘best of the year’ lists, Charli released her second mixtape of 2017 titled ‘Pop 2’ on December 20th. Her non-committal to an album or EP is significant; coining it a mixtape (despite it being for sale) grants a certain level of creative freedom. In the age of Spotify playlists and algorithms, for a major artist to not play by the rules is controversial. ‘Pop 2’ is an eclectic response to the monotony of pop music charts, and a kick in the teeth to those who claim pop music is banal and conventional (I’m looking at you, Adorno).

It’s almost a satire of the top 10 charts, with lavishly auto-tuned vocals and lyrics so repetitive that its almost comical. It subverts everything that you thought you knew about pop music and its defining characteristics. “Go fuck your prototype/I’m an upgrade of your stereotype” she croons on Femmebot. That’s us told.

Pop music is characteristically music that appeals to the masses – hence the name ‘popular music’. The songs always follow a formula. They are predictable, and this familiarity is comforting. ‘Pop 2’ turns this concept completely on its head; there are speed bumps and surprises around every corner. Just when you begin to relax within the safe surroundings of a verse, you are catapulted into a totally unprecedented new section.

There is an impressive catalogue of feature artists on the mixtape including Carly Rae Jepsen, ALMA and Tove Lo, as well as some lesser known ones such as cupcaKKe, Pabllo Vitar and Kim Petras. Each of the songs on ‘Pop 2’ have potential to be bona fide pop hits, but it’s as though Charli took the stems from the sessions and threw in an array of random instruments, textures and a hell of a lot of auto-tune on top of them. The result is a strange experimental/electro-pop hybrid.

Backbeat (feat. Carly Rae Jepsen) opens preceding and is faithful to Jepsen’s synth heavy background, with an infectious rising, joint vocal feature over the lyrics “all alone”. As many songs on the mixtape do, Backbeat comes close to ripping at the seams towards the end as vocals and synths warp into one in a dramatic climax. Both vocals are drenched in auto-tune in a deliberate attempt to make them sound artificial.

Out of the 10 songs on the mixtape, Backbeat is perhaps the most toned back when it comes to the prevailing metallic soundscapes and strange synth sounds. The song is somewhat loyal to both of the singers’ bubble-gum pop origins.

If there is a crowd pleaser on ‘Pop 2’, it is definitely Out Of My Head (feat. Tove Lo and Alma). Charli herself doesn’t appear in the song until the second verse. In most of the songs on the mixtape, the production techniques and guest artists get more airtime than Charli does. By the second chorus, all three voices have woven together seamlessly. Out Of My Head is a pop song that keeps you wanting more; it doesn’t resolve towards the end and it doesn’t deliver the final big chorus.

While a ballad should probably have never made the cut for ‘Pop 2’, listeners will be glad that Lucky did. It’s by no means a traditional ballad (you won’t find any Adele comparisons here), but by ‘Pop 2’ standards, it is. The song is certainly more vulnerable and less-imposing than the other songs on the mixtape.

Being one of two solo tracks on the whole mixtape, Lucky gives Charli a chance to showcase the song-writing talents that have earned her so much acclaim over the past few years. The singer is evidently at her best in the slower, more subdued songs; “you’re so lucky, you get away with it all”. Clever but subtle production techniques such as her voice stuttering over the lyrics “you’re breaking up” give the song an extra finesse.

‘Pop 2’ saves the best until last with the unassumingly titled Track 10. The song sounds like a Mario Kart video game meets 90s Britney. The irresistible hook  – “I blame it on your love, every time I fuck it up, I blame it on your love” – develops throughout the song to the point where it sounds like it’s about to self-combust, complimented by burgeoning metallic undertones that mature into percussion parts towards the end.

The purpose of ‘Pop 2’ was not to show off Charli XCX’s song-writing or vocal talents, but to prove that pop music boundaries can indeed be obscured and blurred. In an era where pop music is so formulaic and prescriptive, the mixtape is a total imposter, it’s the first of its kind. Of course – artists push boundaries all the time in their music, but so seldom do any of these artists have the same amount of influence and audience scale as Charli.

As the title suggests, ‘Pop 2’ transports its listeners to a totally new pop stratosphere. Here, there are no playlists and no Spotify algorithms. No label executives pressuring for top 10 hits. Charli XCX has totally re-imagined the peripheries of the pop genre, and those peripheries may never be whole again.