Post-rock

Post-rock is a type of experimental rock music. It focuses more on making different tones and musical textures than other rock music does. Many post-rock musicians are instrumental. The genre came from indie music communities in the 1980s and 1990s. A lot of post-rock music is inspired by ambient, jazz, and electronic music.
The bands Talk Talk and Slint made some of the first post-rock songs. The word "post-rock" came from a review of an album by Bark Psychosis in 1994. The word has been used to describe many bands with different styles. Many musicians do not like this, because it makes it harder to define what post-rock is.
Sound.
Post-rock is inspired by many genres of music, such as krautrock, jazz, math rock, and avant-garde music. Many post-rock songs are long, and slowly build up the dynamics and timbre of the music. Many post-rock songs do not have any vocals in them, but some do. 
Vocals in post-rock are often used to create sounds instead of sing lyrics. Sigur Rós, a post-rock band known for their vocals, made up their own language for their music. They use the language to make sounds that are "gibberish" but fit "the music".