Ayreon /ˈɛriən/ ⓘ is a musical project by Dutch songwriter, singer, musician and record producer Arjen Anthony Lucassen.

Lucassen writes the music and the lyrics, sings and plays most of the instruments on all of the Ayreon albums, alongside many guest musicians.

Shortly following Universal Migrator came Ayreonauts Only, an album generally meant to be only for diehard fans of Ayreon.

The album itself was the second to not follow a specific storyline; it instead contained alternate versions (With different vocalists or instrumentalists) of existing songs, or the original demos used when recording them.

Starting in 2004, after changing from Transmission Records to InsideOut, Arjen began rereleasing his Ayreon catalog on the new label, with enhancements ranging from basic (The Universal Migrator, issued as a two-disc set instead of two separate albums) to drastic (Actual Fantasy, "Revisited" with completely re-recorded drums, bass, synth and flute).

This album was noticeably darker than previous Ayreon releases, Lucassen attributes this to a depression and his divorce in the preceding year.

The EP features two tracks from 01011001, one from The Human Equation and an Alice Cooper cover (Elected), with vocals by Arjen and Tobias Sammet.

[13] On 7 December 2017, Lucassen stated that a new Ayreon concert would take place on 22 June 2018 at Graspop Metal Meeting, where they would headline the Marquee stage.

Simone Simons and Mark Jansen of Epica, Praying Mantis singer John Jaycee Cuijpers, Marcela Bovio, Bovio's husband and VUUR bassist Johan van Stratum, and Ex Libris members Dianne van Giersbergen and Bob Wijtsma were also featured, with actor John de Lancie acting as narrator.

[19] Ayreon was supposed to headline the Night of the Prog Festival in Germany on 18 July 2020 to perform Into the Electric Castle once again, however the event was cancelled due to the COVID-19 pandemic.

[21] On 13 May 2020, he announced the first member of the cast, actor Tom Baker, providing spoken vocals as the character of "The Storyteller".

[22] The rest of the cast was announced during the following week, also including Tommy Karevik of Kamelot and Seventh Wonder as the lead character of Daniel, Cammie Gilbert of Oceans of Slumber as Abby, Micheal "Mike" Mills of Toehider as The Statue, Amanda Somerville as Lavinia, Paul Manzi of Arena and The Sweet as Henry, Dianne van Giersbergen of Ex Libris as The Soprano, Threshold drummer Johanne James as Abraham, Simone Simons of Epica as The Angel of Death, and Dee Snider of Twisted Sister as Daniel's Father; Marcela Bovio of MaYaN (and Lucassen's former band Stream of Passion) and Caroline Westendorp of The Charm the Fury portray a duo of characters known as the Furies.

[23][24][25] Keyboardist Joost van den Broek, violinist Ben Mathot, and flutist Jeroen Goossens, all of whom had been featured on every Ayreon album since 2008's 01011001, are also returning.

[26] Juan van Emmerloot acted as drummer, making Transitus Ayreon's second album after 2000's Universal Migrator Part 1: The Dream Sequencer not to have Ed Warby on drums, as Lucassen stated that he did not originally conceive Transitus as an Ayreon album, and felt like it would need a completely different style of drummer.

[28] On 13 October 2022, Lucassen announced more Ayreon concerts in September 2023 in Tilburg, in which the studio album 01011001 was performed in its entirety.