Progressive Metal

A subset of Heavy Metal which combines the musical intricacies of Progressive Rock with the heavy, guitar/drum-driven sound of metal. Progressive Metal may also include more overt flavorings of Classical music, such as operatic vocals or symphonic arrangements. A concrete definition of progressive metal is hard to pin down, so the status of many bands as progressive metal can be ambiguous.

Also, see Technical Death Metal and the "Avant-Garde/Progressive Black Metal" section in the Black Metal article.

Notable Progressive Metal bands include:
 * The 3rd and the Mortal
 * 30 Seconds to Mars (also classed as Alternative Rock, Alternative Metal, Post Hardcore, Progressive Rock, Space Rock, and Emo)
 * Agalloch
 * Aina
 * Akercocke (also classed as progressive black metal, Progressive Death Metal, blackened death metal, and probably a number of other things)
 * Amorphis (First album was straight-up Death metal, and their second album was Melodeath/DoomMetal. However, from their third album on, they've been prog metal)
 * Alchemist
 * Arcturus
 * Atheist
 * August Burns Red (mixed with Metalcore)
 * Ayreon
 * Baroness
 * Battle of Mice
 * Between the Buried And Me (mixed with Metalcore and Death Metal)
 * Borknagar
 * Circus Maximus
 * Conception
 * Cynic
 * Death, the first Death Metal band, gradually moved towards prog metal the further along they went with the band. By their last album, The Sound of Perseverance, they were most definitely a prog metal band.
 * Dream Theater
 * Edge of Sanity
 * Epica, one part progressive metal, one part Symphonic Metal.
 * Faith No More
 * Furyu
 * Fates Warning
 * Freak Kitchen
 * Gojira
 * Ill Nino (Enigma only)
 * Isis
 * Liquid Tension Experiment
 * Mastodon
 * Megadeth, although they are best known as a Thrash Band, the experimented with prog elements quite frequently in their music
 * Meshuggah
 * Mudvayne
 * Mutyumu
 * Nevermore
 * Opeth (mixed with Death Metal)
 * Orphaned Land
 * Pain of Salvation
 * Pelican
 * Periphery
 * Porcupine Tree (starting with In Absentia and getting heavier ever since; formerly Progressive Rock / Psychedelic Rock)
 * Queensryche
 * Riverside
 * Savatage
 * Seventh Wonder
 * Shadow Gallery
 * Sik Th
 * Sonata Arctica, started as a power metal band with some progressive elements, went pure progressive with Unia and fused power and progressive evenly with The Days of Grays.
 * Strapping Young Lad, though they also have obvious Thrash Metal roots.
 * SYL singer/guitarist Devin Townsend's solo albums are more unambiguously this.
 * Symphony X (crosses over with Power Metal and Symphonic Metal)
 * System of a Down
 * Threshold
 * Tiamat (Only Wildhoney is properly part of this genre, but some of their other albums have prog elements.)
 * Tool
 * Tourniquet ( also Thrash Metal)
 * Voivod
 * Watchtower
 * X Japan

Tropes that apply to progressive metal:

 * Epic Rocking: Good luck finding a progressive metal band that hasn't ever used this trope.
 * Trope Maker: Probably Queensrÿche or Dream Theater. Fates Warning or Watchtower would count if you don't consider either of them to be Ur example instead.
 * Uncommon Time: Used frequently. Again, pretty much all bands in the genre have used this trope at least occasionally, although some are more blatant about it than others.