Big room house (also spelled Bigroom house and simply abbreviated to "bigroom") is a subgenre of house music, which combines the melodically rich nature of progressive house and trance music with the minimalistic hard or deep subgenres, such as electro house. It is often characterized by sweeping introductions and breakdowns (featuring piano, string, vocal, and pad sounds) followed by a high-energy climactic build-up and a simplistic bass-heavy section that is often referred to as the drop (which often features bass-heavy kick drums, manipulated supersaws synth leads, and Hoover-like sounds). The term "big room" refers to the reverberated drums and synths often found in the "drops", which create the illusion that the sounds are coming from a large enclosed space.