Overview
In music, a breakdown is a part of a song in which various instruments have solo parts (breaks). This may take the form of all instruments playing the verse together, and then several or all instruments individually repeating the verse as solo parts.
A breakdown is a popular musical style particularly in bluegrass, notable examples being Earl Scruggs' "Foggy Mountain Breakdown" and Bill Monroe's "Bluegrass Breakdown".
Disco and later dance music
Disco producer, mixer, and remixer Tom Moulton invented the "disco break" or breakdown section in the early 1970s. Moulton had been remixing a record (”Dreamworld” by Don Downing) which "immaculated" (modulated to a higher key) towards the end, and he wanted to cut parts together that were in different keys. To do this, he separated two sections with non-tonal information. He edited in a section of drums, and the aesthetic effect was pleasing to dancers at the club. The placement was also useful for club DJs, providing a rhythm-only section of the recording over which to begin mixing in the next record. Moulton says his innovation was an accident. The placement followed the pattern of a traditional pop recording: it replaced the bridge typically found in such a record after the second chorus.
A later example is the breakdown in "My Lovin' (You're Never Gonna Get It)" by En Vogue: a sampled male voice can be heard introducing this part of the record (at 3:27) with the sentence "and now it's time for a breakdown". Longer dance tracks often have two, three, or more breakdowns.
From Wikipedia (CC BY-SA 4.0).