Bmaj13#11

Construction

Built from these intervals: 1-3-5-7-9-#11-13. Maj13#11 is maj7 with added 9, #11, and 13 -- all seven notes of Lydian (the major scale with a raised 4th) stacked as a chord. Every scale degree is present: 1, 2 (9), 3, #4 (#11), 5, 6 (13), 7. The #11 avoids the half-step clash with the 3 that plagues the natural-11 versions, so this massive chord has no internal friction. Maximum extension, maximum consonance. Seven notes exceed the six strings of a guitar, so in practice guitarists select the most essential tones.

Harmonic Function

In Roman numeral analysis (uppercase = major, lowercase = minor):

• Imaj13#11 -- the ultimate Lydian tonic statement, containing every Lydian scale degree in a single chord
• IVmaj13#11 -- maximum subdominant extension in a major key; every note is diatonic (belonging to the key's natural scale) when built on the fourth degree
• Complete modal harmony -- represents the entire Lydian mode built vertically, as far as tertian (built by stacking thirds) extension can go

This is the endpoint of Lydian extension. Every note belongs and nothing clashes -- the mode is fully declared.

Character

Luminous and complete. As a member of the extended major chord family, this chord is Lydian taken to its conclusion -- every available extension present, all bright, all consonant. The 13 adds warmth that the purely crystalline maj9#11 lacks, rounding out the top of the chord. Compare to maj9#11: both are Lydian, but maj13#11 is wider and warmer because the 13 fills in the one missing scale degree. Compare to maj13 (natural 11): the #11 clears the 3-11 clash, shifting the sound from Ionian (the major scale) to Lydian radiance.

Related Sounds

These chords are closely related -- each modifies one interval or removes an extension:

• maj9#11 (1-3-5-7-9-#11) -- remove the 13th, still clearly Lydian but missing the warmth of the 6th degree
• maj13 (1-3-5-7-9-11-13) -- natural 11, Ionian rather than Lydian, with the 3-11 clash
• maj7 (1-3-5-7) -- the foundational parent chord at the base of all these extensions
• 13#11 (1-3-5-b7-9-#11-13) -- Lydian dominant (fourth mode of melodic minor), the b7 changes the function from tonic to dominant
• Contains the complete Lydian mode (1-2-3-#4-5-6-7, where 9=2, #11=#4, 13=6) -- all seven notes present

Voice Leading

Voice leading tracks how individual notes move from one chord to the next. With every Lydian tone present, voice leading is about choosing which voices move and which sustain. The full palette means any note can serve as a melody while others hold.

• Imaj13#11 to ii7: The 13 of I becomes the 5 of ii. The #11 moves down a half step to the b3 of ii. The 7 drops to the 5 of ii. Extensions flow into each other with minimal movement.
• IVmaj13#11 to V13: The #11 of IV holds as the 3 of V. The 3 of IV steps down to the root of V. The leading tone anchors the progression while upper voices shift smoothly.
• Imaj13#11 to vi: The 13 of I becomes the root of vi -- a natural pivot where a color tone transforms into a new foundation. The 3 and 5 hold as common tones.

These movements apply in any key -- the intervals are the same regardless of root.

Practice Seeds

Extension stacking. Build from maj7 to maj9 to maj9#11 to maj13#11, adding one tone at a time. Hear each extension's contribution as the Lydian picture fills in. This is how seven-note chords emerge from four-note foundations.

Ionian vs. Lydian. Compare maj13 (natural 11) to maj13#11 (#11). Ionian is the standard major scale; Lydian raises the 4th. One interval separates the complete Ionian mode from the complete Lydian mode -- hear how that single alteration changes the character from complex tension to open radiance.

Nearest-neighbor swap. Play maj9#11, then add the 13. The extra note fills in the last remaining gap in the Lydian scale. Hear the warmth the 6th degree contributes, rounding out what was already bright.

Voicing reduction. Since seven notes exceed six guitar strings, choose which tones to keep. The 5th and root are commonly the first to drop; the 3, 7, #11, and 13 carry the chord's identity. Remove notes one at a time and discover which tones are essential to the Lydian character -- this is how arrangers shape practical voicings from theoretical maximums.