I am just wondering what the difference between a chord progression and a riff is?
My assumptions are that riffs are generally 2 measures long, and they are pretty much classed as being played over a single chord?
My assumptions for chord progressions are that they are generally 4-8 measures long ('cept in blues of course; 12) and the tonal center is dynamic within them?
A chord progression specifies a series of chords, and when they are played:
| C | C | C | C | F | F | C | C | G | F | C | C |
A chord progression doesn't tell you how to play the chords, only what they are and when they change. It doesn't tell you want instrument to use, what inversion of the chord to use, what rhythm or strum pattern, whether to play block chords or arpeggios, or anything like that.
An instrumentalist can take a chord progression and turn it into their own interpretation of a song. For example, a guitarist can make the chord shapes and strum. A user of some "toy" electronic keyboards can just tap the key corresponding to each chord change, and get a full accompaniment!
A riff is a recognisable sequence of single notes or chords, usually played on a guitar.
A riff is (usually) played on top of a chord progression.
A riff is a progression of notes, usually played on top of some chords (could be played a capella, could be played over one chord, could be anything). There isn't any rule that specifies how long a riff is. A riff could be half a measure, could be 3, could be 6.
A chord progression is a progression of chords. A chord progression may or may not have a riff played on top. There isn't any rule on the duration of a chord progression either. A chord progression could be a measure long (with 3 chords) or it could be 12 measures long.
These two are completely different.
A riff is a reasonably short repeated melodic pattern. It may be the melody, it may be used as an accompaniment figure. Finding a riff that works over several different chords or series of chords is a very common technique. Here's a piece that is based on a repeated riff. enter link description here
A chord progression is a series of chords that leads somewhere, typically to the tonic. But it could also lead to an imperfect (resting on the dominant) or interrupted (heading for the tonic but diverted somewhere surprising) cadence.
