Chromatic Passing Notes in Guitar Solos
A chromatic passing tone is a note outside the scale that physically fills a whole-step gap between two neighboring scale or pentatonic notes (see [[what-is-a-pentatonic-scale:the article on the pentatonic scale]]), connecting them with smooth half-step motion instead of a leap.
Where the pentatonic scale has whole-step gaps
In A minor pentatonic (A-C-D-E-G), there's a whole step between C and D, and another between E and G. Those are exactly the gaps a passing note fills: C-sharp between C and D, F-sharp between E and G. The other neighboring pairs (A-C, D-E, G-A) are already a step and a half apart, so a single chromatic note doesn't fit exactly between them.
The passing note belongs on a weak beat, not a strong one
A chromatic note sounds like a connector rather than a mistake when it's short and lands on a weak beat or an 'and' between beats, with the scale notes on either side landing on strong beats. Play C on the pickup, C-sharp on the 'and', D on the next strong beat - the ear hears smooth upward motion, not a stray note.
It isn't the same thing as a chord approach note
A passing tone fills a gap inside the scale itself and isn't tied to a chord change. An approach note is a different device: a chromatic note a half step below or above a specific chord tone, played right before it to emphasize landing on the harmony (see the article on targeting chord tones). Both use the same physical gesture - a half step before the target - but solve different problems: one connects scale notes, the other targets a specific chord.
Drill: one passing note in a familiar phrase
Take a familiar phrase in position 1 of A minor pentatonic, find a spot where it moves from C to D or from E to G, and insert a passing note between them on a weak beat. Play to a metronome so the chromatic note lands exactly on the "and", not sliding onto the strong beat along with the target note.
Try it in practice
Open chord trainer