Progressive alternative music is a merging of traditional progressive rock concepts and alternative styles of music such as metal, punk and hardcore. Many groups have also merged cultural music styles such as Latin and hip-hop.
Progressive alternative music tends to avoid traditional song structures. Most music is not performed following the standard verse-chorus-bridge model. Instead, the music highlights musical interludes and contrasts between sections.
One defining feature of progressive alternative music is the collecting of songs into elaborate and unified sets known as "concept albums." These albums deal with concepts as diverse as history and metaphysics.
Visual art is generally an important aspect of progressive alternative music. Whether on the website, album or in concert, many of these groups and musicians use artistic visual styles to accent the music.
The Mars Volta is one of the most successful progressive alternative music groups. After releasing the single "The Widow," the 2005 album "Frances the Mule" hit number four on the Billboard 200 chart.