The musical definition for the word riff is the origin of the word as we know it today. Garner tells us that it is actually an older word having no connection to its current usage.* Most dictionaries indicate that it is a shortened form of the word “refrain,” which is a repeated portion of a tune. In the traditional song, Clementine, for instance, the refrain is:
Oh, my darlin’, Oh, my darlin’, Oh, my darlin’, Clementine,
You are lost and gone forever, Oh, my darlin’, Clementine.”
In jazz or blues, however, the riff is a much more sophisticated element. The Merriam-Webster Dictionary describes it as an ostinato, a
term which I featured way back in the first month of writing this blog in 2009. It is an almost-subliminal phrase which is repeated over and over again behind the melody of a tune. In jazz a riff is not as subliminal, however. It is right out front.
Jazz lovers go into a state of ecstasy when a musician “takes off” on a riff, sometimes lasting for several minutes. The musician calls upon numerous variations of the theme, then returning to the piece which the band is supporting.
Riff has become a term to be found in the field of stand-up comedy, as well. It is similar, in that the comedienne “goes off” on a theme. If she is talking about popcorn, for instance, and then spends several minutes describing the character of popcorn, its origin, and how you prepare it, she has done a riff. Her main point may be, however, that the harried movie snack clerk accidentally poured a cleaning powder over the corn rather than salt. The riff sets up the joke line.
In comedy a riff needs to be managed. If it gets away from the comedienne she will lose the crowd…who have lost the point. It needs to be long enough to be entertaining, but short enough to hold the attention of the crowd.
The same can be said about a jazz or blues riff. While it may turn out to be the most memorable portion of a song, it is not the main thrust. It is only an amplification of a theme.
Garner points out that riff can easily be confused with a similar word, rift, which means a break or fissure. The two are not to be confused.
Painting Credit: John D. Woodridge
*[Riff} has little discernible relation to the older, mostly obsolete sense of … a string of onions,  the diaphragm, and  the mange; an itchy rash.