Billie's Bounce Walking Bass Line

Charts differ in two spots. Some keep bar 4 on F7 instead of Cm7 F7, and some stay on Bb7 in bar 6 instead of Bdim7 (a few put the Bdim7 on beats 3 and 4 of bar 2 instead). You'll also see bar 11's D7 written as D7b9.

• The root lands on beat 1 of 12 of the 16 chord changes, so the harmony is clear. The rest start on the 3rd or 5th, which keeps the line from sounding like a list of roots.
• 15 of the 15 chord changes are approached by a half step or a whole step, so every new chord arrives smoothly instead of by a jump.
• Non-chord tones sit on the weak beats: 6 on beat 2 and 3 on beat 4. That's where passing and chromatic notes sound intentional instead of wrong.
• No note repeats back to back. A repeated note is the quickest way to make a walking line sound stiff.

• The quick change: bar 2 moves to Bb7, the IV chord, and bar 3 goes right back to F7, so the root moves F, Bb, F across the first three bars.
• A ii-V into the IV chord: Cm7 to F7 in bar 4 sets up Bb7 in bar 5. That's two chords in one bar, two beats each, and you'll see it again in bars 8, 11 and 12.
• A diminished passing chord: the root of Bdim7 in bar 6 sits a half step above Bb (bar 5) and a half step below C, the 5th of F7 in bar 7, so the bass can climb Bb, B, C.
• Roots that climb in fourths: bar 8's Am7 D7 is a ii-V into Gm7, and the roots from bar 8 to bar 11 run A, D, G, C, F, each a fourth above the last.
• A I-VI-ii-V turnaround: bars 11 and 12 (F7 D7 | Gm7 C7) send you back to the top of the form, two beats per chord.

• Charlie Parker, The Charlie Parker Story (1945), with Curley Russell on bass.
• Stan Getz and J. J. Johnson, Stan Getz and J. J. Johnson at the Opera House (1957), with Ray Brown on bass.
• Dexter Gordon, Bouncin' with Dex (1975), with Niels-Henning Ørsted Pedersen on bass.