Here’s the Circle of 4ths starting with C.
C_F_Bb_Eb_Ab_Db_Gb_B_E_A_D_G_C
Now Let’s say we start with Ab.
Ab, Db, Gb, B, E, A, D, G, C, F, Bb, Eb, Ab
As you can see the notes are the same, it is the voicing of the chords that will change depending Key of Song and application of where you are using the Circle. 2-5-1 in the Key of Ab is simply using the appropriate chords to get from your Bb chord (2), to the Eb chord (5), back to the Ab chord (1), recognize that is still a part of the Circle of Fourths (ex. Last 3 notes in the 2nd note example above). I’ll point out each Portion and Application of chords used in the Circle of Fourth’s below again.
/Ab, Bb, C – There, is, No
8. Ab-Ab/EbGBbC, Bb, Ab – Weapon
7. G-G/DbFGBb(7), C/DbEGBb(3)- Formed (Circle of 4th – G, C, F or 7-3-6)
6. F-F/EbFAbC(6), Bb, Ab – Against Me
5. Eb-Eb/DbGbBb(5), Ab-Ab/CGbBb(1) – That Shall (Circle of 4th – Eb, Ab, Db or 5-1-4)
4. Db-Db/EbFAbC(4), Bb, Ab – Not Prosper
(Now look at the last five notes of the Ab ex. Above C, F, Bb, Eb, Ab – all using the circle of 4th 3-6-2-5-1)
3. C-C/BbEbAb(3), FCEb/BbCEbAb(6)– Use this chord instead of previous
2. Bb-Bb/CDbFAb(2) – It Won’t
Eb-Eb/DbFAbBb(5) - Work
1. Ab-Ab/EbGBbC(1), Bb, Ab – Weapon
Yes, we skipped around within the circle, and this will happen with most songs, not sure if you’ll find a song that uses every note in the circle in order chronologically, although it maybe possible. Just try to recognize where you can use the circle and what chords apply in the key your playing. Hope this clears up the example.
