The 12-Bar Blues Bassline Every Piano Left Hand Needs to Learn
The classic 12-bar blues left-hand bassline plays the 1, 3, 5 and 6 of each chord's own root (Bb D F G over Bb7), then grows into a two-bar 1-3-5-6-b7-6-5-3 line, while the right hand comps dominant seventh chords in a swung Charleston rhythm.
Key points
- Play every blues chord as a dominant seventh: Bb7, Eb7 and F7 in the key of Bb.
- The core bassline is 1-3-5-6 of each chord's own root, e.g. Bb D F G over Bb7.
- Extend it to a two-bar line 1-3-5-6-b7-6-5-3, but use the one-bar version on the single F bar.
- Use a Charleston rhythm in the right hand and swing the whole groove.
- Feel beats 2 and 4 and always count the 12 bars.
This lesson by Jason Zac of Nathaniel School of Music teaches the most popular left-hand bassline for 12-bar blues on piano, in the key of Bb. It suits players who know their major scale and basic triads and want their left hand to groove like a bass guitar or trombone instead of just playing chord roots.
The theory: dominant seventh chords
In the blues, every chord is played as a dominant seventh, not a major seventh. To build one, play the major triad, find the root an octave up, then come down a whole step (two semitones). That note is the flat seven.
- Bb7 (I): Bb D F Ab
- Eb7 (IV): Eb G Bb Db
- F7 (V): F A C Eb
Practise these in different inversions so your right hand can find them without thinking. If sevenths feel hard at first, plain triads are fine, but the dominant sound is heavier and more bluesy.
The 12-bar form
The version used here is:
- Bars 1-4: Bb7
- Bars 5-6: Eb7
- Bars 7-8: Bb7
- Bar 9: F7
- Bar 10: Eb7
- Bars 11-12: Bb7
Before any bassline, play just the chord roots in the left hand with the chords in the right hand until you can count the 12 bars and feel each change coming.
Variation 1: 1-3-5-6
Play four crotchets per bar: the root, major third, perfect fifth and major sixth. Over Bb that is Bb D F G. In swaras this is Sa Ga Pa Dha, and singing it helps.
Crucially, you transpose the pattern to each chord's own root, not within the Bb major scale. So Eb gives Eb G Bb C and F gives F A C D. Learn the form line by line: master the four Bb bars, then add the Eb bars, then the final line.
Variation 2: add a pickup
Split the last crotchet of the bar into two quaver (eighth) notes, creating a little pickup that leads into the next bar. In the early stages you can simply hold the right-hand chord while the left hand settles in.
The Charleston right hand
Make the right hand choppier with the Charleston rhythm: a chord on beat 1 and another on the 'and' of beat 2. It is a very idiomatic figure used by blues and jazz players. You can also try a displaced Charleston that shifts the hits to different points in the bar, and alternate between the two.
Variation 3: the two-bar phrase
Stretch the line over two bars: 1 3 5 6 b7 6 5 3. Over Bb: Bb D F G Ab G F D. Use it wherever a chord lasts two bars. Bar 9 (F) has only one bar, so play the one-bar pattern there. Always use the flat seven; the major seven does not belong in this blues sound.
Further twists
Jason Zac adds a rhythmic variation with quavers straddling the end of one bar and the start of the next, and a decorative figure moving around the 6, 5 and b7 that finishes with a quick triplet on 5-6-5. Play that figure fast and lightly, and leave it out on the F bar.
How to practise
- Get the right-hand chords into muscle memory so your attention can stay on the left hand.
- Start slowly and straight, then swing the line as confidence grows.
- Snap your fingers or tap on beats 2 and 4 to feel the blues backbeat.
- Always count the 12 bars aloud.
- Jam with drum tracks, backing tracks or other musicians, since blues is a jamming genre.
Questions about this lesson
What notes are in the 12-bar blues bassline in Bb?
The basic pattern is root, major third, perfect fifth and major sixth of each chord: Bb D F G over Bb7, Eb G Bb C over Eb7, and F A C D over F7.
Do I transpose the bassline within the Bb major scale?
No. In the blues you rebuild the same intervals from each chord's own root, so the Eb bars use Eb G Bb C, not notes taken from the Bb scale.
How do I form a dominant seventh chord quickly?
Play the major triad, find the root an octave up and drop a whole step. For Bb that gives Ab, so Bb7 is Bb D F Ab.
What is the Charleston rhythm on piano?
It is a right-hand pattern with a chord on beat 1 and another on the 'and' of beat 2, a common rhythmic figure in blues and jazz comping.
Practise it
- The Dominant SeventhStudy dominant-seventh harmony through musical examples.
- Swing GardenWork with straight and swung rhythm in an interactive teaching workspace.
- Piano classes at Nathaniel School of MusicLive online or in Bangalore, with a teacher.
- All free music apps40 practice tools for harmony, rhythm, ear training and more.
Related lessons
- The Best Blues Piano Patterns for Both Hands (Swing and Charleston)A classic blues piano groove pairs a left hand alternating root-fifth and root-sixth over each chord (C-G, C-A for C) with a right-hand Charleston rhythm, played legato on the beat and staccato off the beat, counted with the feel on beats 2 and 4.
- 3 Old-School Country Piano Rhythms for Easy AccompanimentOld-school country piano accompaniment uses I, IV and V chords, with the left hand alternating root and fifth while the right hand plays the chords in a waltz, two-beat or swung Western swing pattern.
- How to Play Boogie Woogie Piano Over the 12 Bar BluesTo play boogie woogie piano, swing a left-hand bass line built on the root, 3rd, 5th, 6th and flat 7th against a steady octave root, play short and long right-hand chords over a 12-bar blues in C, and finish with a Dm7–G7#5 turnaround and a C6 ending.
- How to Play Kaisi Paheli Zindagani on Piano (Sunidhi Chauhan) – Full TutorialKaisi Paheli Zindagani is played in Bb major with a swing feel: the intro uses Bb, Gm, Cm and F (a I-vi-ii-V), while the verse and chorus use two bars each of Bb, Cm7 and F7 before returning to Bb.