What is a riff?

A riff is a melodic phrase or pattern of notes that is repeated throughout a song, often serving as its main or most recognizable musical theme. Riffs can be played on any type of instrument, but are most commonly associated with guitar-based genres such as rock, blues, and metal.

Riffs are often characterized by their simplicity and repetitiveness, making them easy to remember and sing along with. They can be used to create a sense of groove or momentum in a song, and help to establish its overall feel and mood. Some of the most famous riffs in music history include those from songs like "Smoke on the Water" by Deep Purple, "Sweet Child O' Mine" by Guns N' Roses, and "Sunshine of Your Love" by Cream.