Ian Anderson, the singer and main songwriter of Tull, repeatedly said that Aqualung was just a "bunch of songs". It's true that it isn't a concept album as such, but it just about classes as progressive in my book. Listen to the title track, "Locomotive Breath" and "Mother Goose", and I think you'll see what I mean. There's little doubt that this is among the top few Jethro Tull albums, and the quality of the songwriting is stunning. The musicianship is also next to none: listen to Anderson's jazz flute solo on "My God", as an example, but the band has one mind even through the most complex passages. This may be just a bunch of songs, but it's one of the best bunch of songs around.

Although I regularly switch between stages of listening exclusively to certain albums and artists, this album holds pride of place as my all time favourite. For me, it's as close to perfection as I've ever heard. It is certainly inspired by classical music, which is especially evident in the 19-minute epic title track. It's hard to believe that five ordinary (or "ordinary") men could produce something so other-worldy. It's certainly not easy to digest, but it's worth every ounce of effort for Rick Wakeman's climactic organ solo, and the "I get up" theme, one of the most beautiful things that they created. "And You And I" is lighter in comparison, though it hardly qualifies for radio play at 10 minutes in length. Siberian Khatru has an inspired guitar riff that never seems to get old, and the kind of energy that few bands can deliver. This music is complex, inspired and almost too good to listen to too much: you can lose the wonder of the music through familiarity. I realise that this isn't for everyone, and that's fine. But I urge you to give this album several listens, to give it the time it deserves. People often rave about "Fragile" being the best Yes album; as brilliant as it is, "Close To The Edge" is a far more accomplished and self-consistent work. For some reason, it always feels like you're doing much more than just listening to music.

Rick Wakeman is, in my opinion, one of the greatest musicians to grace rock music. He studied piano, clarinet and orchestration at the Royal College of Music, but left to become a session musician. This is brilliant, because he had a huge influence in music, if not just giving thousands upon thousands of budding keyboard players that they could be more than just background noise. This work is an absolute masterpiece, and manages to sound epic in spite of the recording limitations of the day. His classical training comes through strongly in his use of strong, recurring melodic themes, which he uses as focuses (sounds less poncy than foci) to build his songs around. The adventurous arrangements have been prepared with great skill, and they consist of a rock band, the largest number of keyboards you can think of, and a choir. His technical skills on the keyboard are nothing short of incredible, and "Jane Seymour" gives you a taste of his ability. His song writing ability is demonstrated at its very best on tracks such as "Catherine Howard" and "Anne Boleyn", which have melodies that you will be humming for days. Not classical, but not quite rock: this is an essential prog album.

I first came across Eno through David Bowie, after I'd worked out that three of my favourite Bowie albums (the Berlin trilogy, Low, Heroes and Lodger) were all written with the man in question. A huge amount in music is owed to this man, who is generally quietly respected by everyone who knows him. The greatest of his legends is arguably "My Life", which still needs a genre title that hasn't yet been invented. Him and David Byrne put their heads together and produced something so unusual and influential that it's still a challenge today. To be perfectly honest, it took me about five or six listens to get a glimpse of why it was so good, which is more than usual. Now it's one of my most prized albums, and gives me a similar feeling to that of returning home. This is essential music.

After Roger Water's disappointing swan song with Pink Floyd, "The Final Cut", critics were unanimously pleased that his first solo album, "The Pros and Cons of Hitchhiking", showed the same creativity and inspiration as the albums produced during the height of Pink Floyd's career. "Amused To Death" is his third album, and regarded by many to be his best. It is both musically and lyrically amongst Waters' very best work. Personally, I think that he found his niche when writing "The Wall" (1979), and Amused follows that similar eclectic musical style. Tracks like "Perfect Sense", "It's a Miracle" and "Amused to Death" show him at his very best.

I came across Arcade Fire through David Bowie, as he gave Funeral considerable praise when the Canadian band had very little international fame, calling it the year's essential album. They probably owe him a lot for their commercial success, but the music speaks for itself. The opening track sets an atmosphere unlike any other I've experienced, due to excellent musical craft, unusual arrangements and Win Butler's tense and strangled vocals. Though it is often dubbed as being "indie", it is highly eclectic, and transcends genres within single songs. There isn't a weak track on the album, which flows from the operatic to the exposed in no time at all. I generally avoid indie music, on the basis that it's almost always boring, but this album blows everything else out of the water.

Sigur Rós are an Icelandic band whose music, though unique in style, harks back to the days of 70's progressive rock. They are often given the relatively obscure tag of "post-rock". I was first introduced to the band through "Takk", and it is still my firm favourite of all their albums. The album feels epic in proportions right from the introduction, and carries an ambiance that no other band has ever achieved. The band have a strong sense of melody, and their instrumentation is close to perfect. The result is ethereal, and the album has an ability to transport you from wherever you are to a completely different world. There are moments on this album which will stay with me forever, like the repeating strings at the end of Andvari, the climactic heights of Mílanó and the beautiful introductory chords of Heysátan (granted, that's an unfortunate name in English). Once you can get over the sheer weirdness of the vocal style, and eventually come to love it, you'll probably understand why I'm making such a fuss.