Try this: Go to your instrument and play a C-major scale from top to bottom (C B A G F E D C). Play these as evenly spaced eighth notes in 4/4 time.
You will notice that the final note, the lower C, does not land on a solid beat (in this case, that would be beat one). Instead, it lands on the last eighth note of the previous measure.
Assuming that we want our C to land on beat one, as a solid “target note,” here’s a common and jazzy sounding solution.
C, B, A, G || F, E, D-flat, B || C
We now have the required eight notes to fill one measure, and the final C lands on beat one of the next measure – voila!
WHY DO I CALL THIS A HALF-STEP SANDWICH?
Because the final target note, C, is now sandwiched between two notes, each one a half-step away, with one note on top, and the other underneath.
The half-step sandwich can be heard a lot in jazz, and the target note typically falls on a solid downbeat.