A riff in A major pentatonic on 6-string bass

The riff plays A on string 1 at fret 10, E on string 2 at fret 12, C♯ on string 2 at fret 9 and A on string 1 at fret 10, on one, two, the and of two and three.

A riff is a short musical idea, a few notes with a rhythm, that you repeat and move around. There are no rules for making one, and this is not a riff you need to learn. It is one of a million possible riffs, chosen because everything done to it here can be done to any riff, including your own. It uses four notes in Box 1: the root, up to the 5, down to the 3, and home. They fall on one, two, the and of two and three, and the last note rings to the end of the bar. Every note lies between frets 9 and 12, under your hand, and the riff changes string twice. The faint dots show the rest of the box, the same notes the scale page draws.

Over A: A rest, E rest, C♯ rest, A rest. Over E: E rest, B rest, A pull, E rest. Over F♯m: F♯ rest, C♯ rest, B pass, F♯ rest. Over D: D borrow, A rest, F♯ rest, D borrow.

In a key, the riff moves by scale degree rather than by fret. It keeps its contour but starts from each chord's root, in the same position, so its shape adjusts to the scale and every note stays in A major. The root of D is not in A major pentatonic, so for that chord the riff moves as a shape instead: for D it moves five frets up on the same strings. A riff that moves always comes home, because its last note is the new chord's root. What changes is how the notes on the way there sit against each chord. Over E, A leans. Over D, D is borrowed, a chord tone the box does not contain. Over A and F♯m, nothing leans. On the necks, a dot with a tick marks a leaning note, and a diamond marks a note the box does not contain.

Over A: A rest, E rest, C♯ rest, A rest. Over E: A pull, E rest, C♯ pass, A pull. Over F♯m: A rest, E pass, C♯ rest, A rest. Over D: A rest, E pass, C♯ pass, A rest.

You can also leave the riff where it is and let the chords move underneath it. Played this way, it does not always come home. Over E, the last note leans: A wants to fall to G♯. The E that passes over F♯m and D becomes a note to rest on over A and E. The C♯ that passes over E and D becomes a note to rest on over A and F♯m. The same four notes say something different over each of the four chords. Soloing works the same way, and the lesson is the same: always know which note you are on against the chord.

Upside down plays A C♯ E A. Backwards plays A C♯ E A. Up a step plays B F♯ E B. Backwards and upside down plays A E C♯ A.

Each version keeps the rhythm and changes only the contour, the rise and fall of the notes. Upside down goes down wherever the riff went up. Backwards plays the same notes in reverse order. Up a step starts one scale degree higher and keeps the shape. Repeating an idea a step higher like this is called a sequence, and it makes a riff sound like it is developing rather than simply repeating.

A riff you can move is far more useful than one you can play in only one place. This particular riff does not matter. What matters is hearing the same few notes say something different over each chord, and knowing that you chose them before the chord arrived.