Candidates for the Big 4 of Progressive Rock/Metal

The Top Ten
1 Pink Floyd Pink Floyd are an English progressive rock band formed in 1965 in London, England. They achieved international acclaim with their progressive and psychedelic music. The band consisted of 5 members - David Gilmour (Vocals and Guitar), Syd Barrett (Vocals and Guitar), Nick Mason (Drums), Roger Waters (Vocals and Bass), and Richard Wright (Vocals and Keyboard). Barrett was replaced by Gilmour in 1968. ...read more.

Definitely. Don't know if they started it or not but they've been always a great prog rock band. And my favorite.

2 Rush Rush was a Canadian progressive rock band that was formed in 1968. The band has had an iconic lineup since 1975, which included Neil Peart (Drums, Percussion), Geddy Lee (Vocals, Bass, Keyboards), and the guitarist, Alex Lifeson. Peart passed away after a 3 year battle with brain cancer in January of ...read more.
3 Dream Theater Dream Theater is an American progressive metal band from Boston, Massachusetts. The band was formed in 1985 under the name of "Majesty", only to change its name to Dream Theater later. ...read more.
4 Queensrÿche Queensrÿche is an American progressive heavy metal band formed in 1982 in Bellevue, Washington, out of the local band the Mob. They released their self titled EP in 1984, but didn’t gain notoriety until the release of their critically acclaimed album Operation: Mindcrime in 1988. As of now, they ...read more.
5 Genesis Genesis are an English rock band formed at Charterhouse School, Godalming, Surrey in 1967. The most commercially successful and long-lasting line-up includes keyboardist Tony Banks, bassist/guitarist Mike Rutherford and drummer/singer Phil Collins.

If we were ranking these bands in terms of influence and who was prog first, it would be Yes, King Crimson, ELP, and Genesis.

6 Tool Tool is an American alternative metal/progressive metal band, that was formed in 1990. ...read more.
7 Opeth Opeth is a Swedish progressive death metal band from Stockholm, formed in 1990 by David Isberg, who invited Mikael Akerfeldt into the band as a bassist. Isberg ended up leaving the band, which lead to Mikael becoming the band's vocalist, guitarist, principal songwriter, and driving force. Along with ...read more.
8 Mastodon Mastodon is an American heavy metal band from Atlanta, Georgia, formed in early 2000 and composed of bassist Troy Sanders, guitarists Brent Hinds and Bill Kelliher and drummer Brann Dailor.
9 Symphony X Symphony X is an American progressive metal band from Middletown, New Jersey. Founded in 1994, the band consists of guitarist Michael Romeo, keyboardist Michael Pinnella, drummer Jason Rullo, lead vocalist Russell Allen and bassist Michael Lepond.
10 Yes Yes is an English progressive rock band formed in 1968 by bassist Chris Squire and singer Jon Anderson. They first achieved success in the 1970s with a progressive, art and symphonic style of rock music. Their best known song is their 1971 hit "Roundabout" off of their album Fragile.
The Contenders
11 King Crimson King Crimson were a British progressive rock band that was formed in 1969. While the band has had numerous lineup changes, the head of the band has always been Robert Fripp (guitar). However, the most notable lineup is between 1972-75, consisting of Fripp, John Wetton (bass/vocals), Bill Bruford (drums), and David Cross (strings/keyboard). The band is most well-known for their debut album "In the Court of The Crimson King", with which they made a large impact on the progressive rock genre.

Wow you seem to take pleasure in leaving out the band that invented the genre itself. Without In the Court of the Crimson King, none of these bands would have been as good as they were (or even exist). Progressive Rock's big SIX: Pink Floyd, Yes, Genesis, King Crimson, ELP, Jethro Tull

BAdd New Item