B Minor Magic: A Deep Dive into “Nuestro Juramento”
Welcome to the party! Today, we are breaking down one of the most iconic Latin American anthems ever recorded: “Nuestro Juramento” by the “King of the Bolero,” Julio Jaramillo.
While originally performed in various keys, transposing this classic to B Minor (as seen in our custom UGP lesson graphic) is a game-changer for guitarists. It allows for deep, resonant barre chords and easy access to the “secret” notes of the harmonic minor scale.
The Foundation: The Bolero Rhythm & Chord Library
Before we analyze the structure, we have to find the “heartbeat.” The Bolero is defined by its sophisticated, driving pulse.
The “Bass-Strum” Method
To get that authentic sound, don’t just strum across all the strings. Use the Bass-Strum approach:
- Beat 1: Strike the Root Note of the chord with your thumb (P).
- Beat 2: A sharp, rhythmic down-strum with your fingers (i/m).
- Beat 2 &: A quick, light up-stroke to add “air.”
- Beat 3 & 4: Two steady down-strums to round out the measure.
Your B Minor Toolkit
Referencing our lesson graphic, here are the primary chords you’ll need. Notice how we balance the dark “i” chord (Bm) with the bright “III” chord (D Major).
| Chord | Role in B Minor | Vibe |
| Bm | Tonic (i) | The home base. Melancholic and deep. |
| Em | Subdominant (iv) | Adds the “longing” emotional weight. |
| F# | Dominant (V) | The tension that pulls you back home. |
| D | Relative Major (III) | Provides the “lift” in the chorus. |
| A | Seventh (VII) | The bridge between the minor and major sections. |
| C# | Secondary (II) | A “passing” chord used to lead into the F#. |
Part 1: The Intro Analysis (The Main Theme)
The intro sets the stage with a classic circular progression.
- Progression: Bm – Em – F# – Bm (Played twice)
- Structure: 8 Bars Total (4 bars per cycle)
- Analysis: This section is all about establishing the “i – iv – V” relationship. The # chord is the star here—the A note within that chord creates the “leading tone” tension that makes the resolution back to Bm feel so satisfying.
Part 2: The Verse Analysis
The verse tells the story, shifting from the sorrow of B Minor into a brief moment of light.
- Progression: Bm \ Em \ F# \ Bm \ D \ A \ F#m \ Em \D \ C# \ F#
- Structure: 16 Bars Total
- Analysis: * Bars 1-8: Stays grounded in B Minor.
- Bars 9-12: Moves to the Relative Major (D Major). This mirrors the lyrics as they shift from sadness to a declaration of love.
- Bars 13-16: A descending walk-back through C# to the dominant F#, setting up a “half-cadence” that leaves the listener waiting for the chorus.
Part 3: The Chorus Analysis
The chorus is where the “Oath” (Juramento) is made, and the music reflects that strength.
- Progression: A – D – B7 – Em – A – D
- Structure: 16 Bars Total
- Analysis: * Bars 1-8: We lean heavily into D Major.
- Bars 9-16: We introduce a Secondary Dominant (B7). This isn’t naturally in the key of B Minor, but it’s used to “force” a transition into Em. This sophisticated chord choice is exactly what gives Boleros their professional, jazzy edge.
Part 4: Applying the B Minor Scale (Natural vs. Harmonic)
Look at the B Min/D Maj Natural Harmonic Scale diagram on the lesson sheet. To play like a pro, you have to know when to switch your scale.
- Over Bm and Em (The “Story”): Use the B Natural Minor scale. It’s smooth and flows perfectly over the minor chords.
- Over F# (The “Pivot”): You must switch to B Harmonic Minor. By raising the A to an A# (Check the 11th fret on the A-string or 8th fret on the G-string in the diagram), you hit the “Major 3rd” of the F# chord.
Underground Tip: That A# is the “Secret Sauce.” Targeting that note right as you transition back to the Bm chord is how you get that authentic, haunting Latino guitar sound.
