Ayreon is a musical project created by Arjen Anthony Lucassen, a Dutch multi-instrumentalist, singer, songwriter, arranger, and producer. His music is usually defined within the parameters of progressive metal, or progressive rock, but also features interwoven strains of power metal, folk, electronica, experimental, and classical music. The majority of Ayreon's albums are dubbed "rock operas" (or "metal operas") because they contain complex plot lines and large casts of characters -- each represented by a unique vocalist -- performed by a revolving-door, international cast of top-flight musicians. Ayreon's grandly conceived third album, 1998's Into the Electric Castle: A Space Opera, wed Greek mythology to science fiction and featured no less than eight singers, Fish and Anneke van Giersbergen among them. 2004's The Human Equation included symphonic strings and another large cast of vocalists. Lucassen even flew Mayan leader singer/violinist Marcela Bovio from Mexico for the sessions. 2008 saw the issue of 01011001, a concept outing that desired to trace the "secret history" behind ASCII binary text characters. 2017's The Source proved Ayreon's most grandly conceived spectacle to date, in studio and on tour. The enormous cast of the musical-theater-meets-progressive-metal production asserted a relatively straightforward sci-fi profile, though its labyrinthine concept narrated an actual prequel to 01011001 -- some of the current songs included lyrics that were sung in binary code.

Lucassen formed Ayreon in 1994 and released the project's first album, The Final Experiment, the following year. The more ethereal Actual Fantasy followed in 1996, and from there Ayreon only got more elaborate. Released in 1998, Into the Electric Castle was a campy sci-fi concept work spanning two discs and featuring guests like ex-Marillion singer Fish and the Gathering's Anneke van Giersbergen. Next up was Universal Migrator, another double-disc set whose volumes were issued separately under the subtitles Part I: The Dream Sequencer and Part II: Flight of the Migrator. These featured even more guest appearances, most notably Tiamat's Johan Edlund and Iron Maiden's Bruce Dickinson, plus current and former members of Gamma Ray, Primal Fear, Helloween, Stratovarius, and Symphony X; musicians included Rocket Scientist's Erik Norlander and ex-Gorefest drummer Ed Warby. Released in 2004, The Human Equation traded sci-fi for medical drama, taking place in the mind of a coma patient recovering from a car crash. It featured the usual slew of guests, including Opeth's Mikael Åkerfeldt, Devin Townsend, and Dream Theater's James LaBrie.

The ambitious, tech-heavy 01011001, which arrived in 2008, featured 17 different vocalists -- more than any other Ayreon album to date -- and brought to a close much of the narrative mythology that had begun with 1995's The Final Experiment. Lucassen returned in 2013 with a new work, The Theory of Everything, inspired by the films A Beautiful Mind and Rain Man. Theater Equation, a concert album/DVD featuring cast, choir, and a small orchestra delivering a rousing performance of 2004's Human Equation, followed in 2016. A year later, Ayreon's ninth studio LP arrived; The Source was a concept album prequel to 2008's 01011001. In 2018, Lucassen issued Ayreon Universe, a massive best-of concert celebration of the Ayreon catalog that was filmed in the Netherlands the year prior.

In March 2020, Ayreon released the double disc/Blu-ray of Electric Castle Live and Other Tales. During the fall of the previous year, Lucassen booked a theater in Tilburg for four nights to perform the rock opera Into the Electric Castle complete with mise-en-scène. He was able to re-recruit the original singers from the studio album including Anneke van Giersbergen, Fish, Damian Wilson, and Edward Reekers. In September, Ayreon returned with the studio album Transitus. Its nearly Shakespearean plot is set on the estate of a 19th century aristocratic patriarch (Dee Snider), and its story line revolves around the forbidden love affair between his son Daniel and the servant girl Abby. As the tale sprawled across time and space, Lucassen included a host of supernatural characters as well. The project's narrator was Tom Baker of Dr. Who fame. ~ Steve Huey, Rovi