For years, rumours of a new Portishead album have been swirling about the Internet, rumours that have always turned out to be false, fake, or untrue. To a degree, the mysterious "third album" became something of a trip-hop "Chinese Democracy" or "Duke Nukem Forever", something that was supposedly in the works, but which nobody except the hopelessly optimistic actually expected to see.

This is why I did not believe it at first when I heard that Portishead were debuting new songs at concerts, and preparing this album for release. Upon finally giving in and checking to make sure that the tales were true, I was struck by another probable problem; in the eleven years since their self-titled second album, the expectations that I had built up about this article were phenomenal. No matter how polished and beautiful the album was, there was no way it could measure up to what I was imagining in my mind, was there?

To my immense surprise though, the minimally titled "Third" has met those expectations, and then some. My fears of a rehash of "Dummy" to please the fans were unfounded, because this album is as sprawling, creative, and experimental as the first two albums were, borrowing sounds from them but striking out in new directions with alarming regularity, creating a record that sounds at the same time familiar and unsettling.

The most obvious place to start is the first single Machine Gun, which has been described as sounding like two drum machines fighting. It's certainly like nothing else that the band has ever released, being abrasive, noisy, and overtly jarring; this is one song that is not going to get picked up to advertise luxury cars on television. It goes nicely with opening track Silence, which would almost sounds like a classic Portishead track, if it weren't for the sudden and abrupt ending to the song, which perhaps shows how far the band are willing to go to subvert your expectations and provide an unsettling listening experience.

You cannot talk about unsettling songs on this album though without discussing The Rip, which is probably my favourite new song out of the batch. Starting out with a gently picked acoustic guitar, it at first seems as if it's going to be a gentle folk song. At the second verse though, the electronica starts fading into the music, replacing the acoustic guitar with an altogether harsher and more mechanical feel. Gibbon's vocals are stretched to impossibly long durations over the cycling, circular melody, creating an uneasy and disquieting atmosphere around the song.

There are other highlights on the album of course, the ukulele barbershop of Deep Water is far too interesting to be thrown aside despite its short runtime, and Plastic brings back vividly the reasons that people started to get into this band in the first place. But to be honest, these are things that need to be heard to be understood, not merely described on paper.

"Third" is a difficult album in places, but it's also an album that makes more and more sense the more that you listen to it. After eleven years, Portishead have not only proved that they have not gone stale and that they can still meet expectations, but they've also emphatically demonstrated that they're still one of the most creative and inspired musical acts out there. Let's hope that we don't have to wait another eleven years for another album.