Rock operas, concept albums, song cycles and oratorios all differ from a conventional rock album, which usually includes songs that are unrelated to each other in terms of storyline. More recent developments include metal opera and rap opera (sometimes also called hip-hopera). The category a particular work falls into is, to some extent, defined by the intent and self-definition of the work by its creator, as long as the creator's interpretation does not stray too far from the accepted definition of what constitutes a rock opera. The formal distinction may be that the rock opera tells a coherent (if sometimes sketchy) story, often with first-person lyrics sung by characters; while a concept album or song cycle sets a mood or maintains a theme. Some albums share characteristics of more than one category. Tommy, one of the best known rock operas, also had a rock musical production. On a technical note, it is often inaccurately stated that the phrase "rock opera" is, in terms of both music and theater, a misnomer. The term is only a misnomer when it is incorrectly applied to a work that has been miscategorized. Opera consists of individual singers acting out a specific character within a drama. The same is also true of a legitimate rock opera. If a work consists of singers who sing a story, but do not act it out, it is not a rock opera, and should not in the traditional sense be categorized as such.
Alternatively, the term rock opera may have originated at an informal gathering of Pete Townshend, guitarist for The Who, and some friends at some point that same year (i.e., 1966). Townshend is said to have played a comedy tape to his friends called Gratis Amatis, and one of his friends is said to have made the comment that the odd song was a "rock opera". (Kit Lambert, the Who's producer, is then said to have exclaimed "Now there's an idea!")
Whatever the origin of the term, the earliest completed and recorded example of a 'rock opera' appeared later in 1966 - Townshend's "A Quick One While He's Away" on The Who's second album, A Quick One. It was a nine-minute suite of short songs telling the operatic story of the seduction of a young girl guide (Townshend) by an engine driver named Ivor (played by John Entwistle).
Then an Alley, also known as The Beat Opera, was conceived and staged by Tito Schipa, Jr., composer and director, son of the tenor Tito Schipa, at the Piper Club in Rome, Italy, in May 1967. While Then an Alley, an adaptation of 18 Bob Dylan songs made to fit into a scenic background, made a moderate splash in its country of origin, it went completely unnoticed elsewhere in the world. Schipa Jr. later went on to write and stage the work Orfeo 9 at the Sistina Theater in Rome. It became the first ever staged original Italian rock opera when it debuted in January 1970. Orfeo 9 became a double album and a film under the musical direction of future Academy Award winner Bill Conti.
In November 1967 the Montreal group The Influence travelled to New York to record a 'mini-opera', "Mad Birds Of Prey", and other songs for their only album. A few months later, in 1968, Britain's The Pretty Things released S.F. Sorrow, the first attempt by a rock band at a single, narrative-based thematic concept expressed over an album's worth of songs. S.F. Sorrow outlined a coming of age story focused on protagonist Sebastian F. Sorrow, although the storyline was not as coherent as those to be found in later rock operas.
In 1969 Pete Townshend and The Who released Tommy, the first of The Who's two full-scale rock operas (the other is Quadrophenia), and the first musical work explicitly billed as a rock opera. [In some older publications it is called Tommy (1914–1984).] The album was largely composed by Townshend, with two tracks contributed by bassist John Entwistle and one attributed to drummer Keith Moon, although actually written by Townshend. An earlier song by blues artist Sonny Boy Williamson II, "Eyesight to the Blind", was also incorporated. Tommy remains one of the most famous rock operas, with concert, film, ballet, and theatrical productions mounted over the course of four decades. The Who would later release another rock opera, Quadrophenia (1973), also made into a film, and a mini rock-opera, Wire & Glass (2006), from Townshend's larger concept of The Boy Who Heard Music, and included on The Who's 2006 album Endless Wire.
In 1973, The Who released their second full rock opera "Quadrophenia." It is about a early 1960's teen living with a personality disorder.
Genesis wrote the rock opera The Lamb Lies Down on Broadway, about a juvenile delinquent called Rael who lives in New York and enters in the underground world, searching for a missing part of himself, the story rolls into lust, deep creatures, madness and redemption.
In 1979, Pink Floyd's rock opera The Wall, written primarily by Roger Waters, was released. As with Tommy, The Wall has been staged as an elaborate theatre performance; by Pink Floyd in 1980 and 1981, and by Waters in 1990 (at the Berlin Wall). The plot was also used for the feature film Pink Floyd The Wall, and Waters has been adapting the story for a Broadway-style production. Also, David Bowie made the rock-opera 1.Outside, a groundbreaking album for Bowie's 90's career. In 1996, John Miner staged the rock opera Heavens Cafe at the Flamingo Theater in Las Vegas, and again in Los Angeles in 2004.
Some heavy metal bands have released albums inspired by rock operas; often in a progressive metal framework. In some cases they have overlapped considerably with the format of metal concept albums. Queensrÿche's fourth album Operation: Mindcrime expanded the genre from their previous three rock operas by bridging rock opera with real opera and a stage production complete with the story playing on jumbotrons in live versions and DVD releases. Albums by W.A.S.P. (The Crimson Idol, The Neon God: Part 1 - The Rise, The Neon God, Pt. 2: The Demise), Savatage, Dream Theater, Ayreon, Kamelot, Dimmu Borgir, Pain of Salvation, King Diamond, and the album Elven Manuscript are a few examples of metal opera albums. The Italian progressive metal band Rhapsody of Fire (formerly "Rhapsody") released several complementary albums that each continued a single mega-"DragonRock" opera. Punk rock opera is a term coined by the pop punk band Green Day to describe their 2004 album, American Idiot. Rock operas have been written in other languages as well, such as Gaia II - La Voz Dormida in 2005 by the Spanish rock group Mägo de Oz. On September 22, 2005 rock band Ludo released a rock opera entitled Broken Bride. In 2006, New Jersey rock quintet My Chemical Romance released an alternative rock opera, titled The Black Parade, about a man dying from cancer. Another one is a project by Edguy's singer and main songwriter Tobias Sammet. The opera is called Avantasia and has received critical success and has spawned 3 albums and two EP's. Each features many well known rock musicians.