Critics might complain that modern pop music is soulless and artificial - but a new'AI popstar' takes that to a whole new level. Anna Indiana, a self-described AI singer-songwriter, has been ridiculed after releasing her first single. In a video posted to YouTube, Anna performs a pop song to a backing track of piano, guitar, and drums. Introducing itself, the AI explains: 'Everything from the key, tempo, chord progression, melody notes, rhythm, lyrics, and my image and singing, is auto-generated using AI.' However, music fans have not reacted well to the release, calling it'horrifying' and'unnerving'.

In fact, a recent study named it the highest earning song on Spotify in the UK, despite it being released by The Killers 20 years ago. The track has so far brought the Las Vegas-born band more than £1 million in royalties ($1,254,087) through the streaming service. Indeed, since 2004, 'Mr Brightside' has spent 358 non-consecutive weeks in the UK singles charts, and is currently at number 62. But why exactly has Mr Brightside stood the test of time? MailOnline takes a look at the science behind this rock anthem.

The second we get in the car, my son strikes up his familiar tune. "I want my playlist, Mum!" Put your belt on, young man. I get a second's sweet peace as I hear the clunk-click. I need my playlist right now!" The playlist of my nearly-nine-year-old's favourite pop songs, usually on shuffle, starts to shake through the car. I give in to his nagging often, but I know why I do. I remember the joy of becoming a music fan, discovering new sounds, worlds and ideas through verses and choruses, through the giddy rushes of rhythms and melodies. I also know that my experiences were very different to his. At his age, I had to hang around the radio for hours or wait until Top of the Pops every Thursday, hoping that a song I loved would appear. These days, my son just asks Alexa. By my early teens, if I wanted to own an album, the process was a little more convoluted: save £9.99 of pocket money, beg my mum to drive me to Woolworths five miles away, pray that they had it, and if they did, play it ...

Natural Language Processing (NLP) is a discipline of AI which enables machines to understand and process human language. The project was about rewriting an existing song in a way that gives the song scientific or technological meaning. The project was based on simple NLP algorithms and not on big models like GPT-2, and still yield good results. The first step before the algorithmic tasks was to download a song's lyrics. In order to make things more interesting, I decided to download a random song each run.

In 2014, music fans and critics began paying close attention to a mysterious group of artists who'd started releasing tracks online. They were part of PC Music, a loose electronic-music collective that functioned more like a conceptual-art project. Led by a young, inventive producer from London named A. G. Cook, PC Music, and its affiliates, rejected a dark, murky strain of underground electronic music that was beloved at the time. Instead, they latched onto the most exuberant and absurd elements of pop, making cutesy, theatrical songs that sounded a bit like children's music, but with an unsettling aftertaste. If mainstream pop is designed to make people feel as if they're on common ground with all of humanity, this music made listeners feel like they were in on a very specific joke.

Pop songs will get shorter on average by the end of this decade because of faltering attention spans and'skipping culture' on streaming services, experts say. Attention spans of music fans has dropped from 12 seconds to eight since the year 2000, according to research from Samsung. As a result it's more important than ever for musicians to draw listeners in early, keep the overall length of a track short and'load choruses up front'. On music streaming services like Spotify, artists don't get royalties from a song being played if the listener doesn't get beyond the first 30 seconds. By 2030, it will therefore be more important than ever for songs to quickly progress to the next track on an album before listeners get bored, the experts say.

In the end most teams used smaller models that produced specific parts of a song, like the chords or melodies, and then stitched these together by hand. Uncanny Valley used an algorithm to match up lyrics and melodies that had been produced by different AIs, for example. Another team, Dadabots x Portrait XO, did not want to repeat their chorus twice but couldn't find a way to direct the AI to change the second version. In the end the team used seven models and cobbled together different results to get the variation they wanted. It was like assembling a jigsaw puzzle, says Huang: "Some teams felt like the puzzle was unreasonably hard, but some found it exhilarating, because they had so many raw materials and colorful puzzle pieces to put together."

Old songs, new tricks: Computer-generated music has been a thing for 50 years or more, and AIs already have impressive examples of orchestral classical and ambient electronic compositions in their back catalogue. Video games often use computer-generated music in the background, which loops and crescendos on the fly depending on what the player is doing at the time. But it is much easier for a machine to generate something that sounds a bit like Bach than the Beatles. That's because the mathematical underpinning of much classical music lends itself to the symbolic representation of music that AI composers often use. Despite being simpler, pop songs are different.

Have you ever noticed that, after 6 p.m. on weekdays, you tend to listen to harmony-laden, lo-fi, guitar-based songs with medium-to-fast-paced rhythms and a strong backbeat -- but you'll skip ones that are too distorted? As opposed to weekend mornings, when you follow up a local news podcast with slower piano tracks sung by a solo female vocalist, with strings and horns, angular melodies, multiple sections (but no solos) and a touch of melancholy throughout? Chances are, you've never thought about your listening choices in such a detailed way. But Pandora's musicologists and scientists have, and that's how -- with the help of artificial intelligence, machine learning and the analysis of the listening habits of its more than 65 million monthly users -- it knows which song you'll want to hear next. "We treat every individual very specially, and focus on contextual recommendations to understand what you like, what you listen to," says Oscar Celma, Pandora's vice president of data science, of how the company maps the DNA of every piece of audio in Pandora's millions-wide song library and compares that with explicit and implicit user preference feedback to yield bespoke programming.

There's a Nirvana song that you may not have heard that, ironically, describes why you have heard another Nirvana song, "Smells Like Teen Spirit," which dominated the airwaves in the early '90s and still endures today. It's called "Verse Chorus Verse" and it follows the song structure it's named for, which most pop songs, including "Teen Spirit" and recent smashes like "Old Town Road," rely on. The only weird thing, though, is that the song is about frontman Kurt Cobain's chronic stomach pain and the medications he illegally took. That title is a play on a common dig at pop songs--all of them sound the same. Now, two student researchers at the University of San Francisco have leveraged Spotify data to figure out if that's really true.