A riff is a short, catchy sequence of notes that repeats throughout a song, usually played on guitar or another instrument. The opening notes of “Smoke on the Water” by Deep Purple form one of rock music's most famous riffs: a simple pattern that grabs your attention and sticks in your memory. A good riff becomes the heart of a song, the part you remember and want to hear again.

Riffs differ from melodies, which flow and change more. A riff locks into a groove and repeats, creating energy and drive. Blues, rock, and jazz musicians built entire songs around memorable riffs. Keith Richards of the Rolling Stones created the unforgettable opening riff to “Satisfaction,” while Jimi Hendrix built “Purple Haze” around a distinctive guitar riff that defined the sound of the 1960s.

The word also means to improvise or speak freely about something. When comedians riff on stage, they create jokes spontaneously rather than following a script. A teacher might riff on a topic, exploring ideas as they come to mind. This meaning connects to jazz, where musicians riff by improvising variations on a musical theme, playing what felt right in the moment.