# B♭ Major 9th piano chord (B♭maj9) B♭maj9 contains B♭, D, F, A and C. A major seventh with the ninth added on top. B♭ is a black key; D, F, A and C are white. - Canonical page: https://piano.org/chords/major-9th/b-flat/ - Entity: chord:major-9th:b-flat - Notes: B♭ D F A C - Formula: 1 3 5 7 9 - Intervals from root: P1, M3, P5, M7, M9 - Interval stack (semitones): 4 3 4 3 - Also written: B♭maj9, Bbmaj9, B♭ major 9th - Parameters: A440, 12-TET, 165 mm octave, spans centre to centre ## Construction | Degree | Note | Interval from root | Semitones | | --- | --- | --- | --- | | 1 | B♭ | Perfect unison | 0 | | 3 | D | Major third | 4 | | 5 | F | Perfect fifth | 7 | | 7 | A | Major seventh | 11 | | 9 | C | Major ninth | 14 | ## Fingering Rest your right hand over the notes with finger 1 on B♭, finger 2 on D, finger 3 on F, finger 4 on A, finger 5 on C. The left hand mirrors it. Right hand 1-2-3-4-5, left hand 5-4-3-2-1. Source: piano.org fingering method v1. ## Inversions | Position | Bass | Notes in order | Figured bass | Span | | --- | --- | --- | --- | --- | | Root position | B♭ | B♭3 D4 F4 A4 C5 | 9 | 14 st, 193 mm | | First inversion (B♭maj9/D) | D | D4 F4 A4 B♭4 C5 | 7/6/5 | 10 st, 138 mm | | Second inversion (B♭maj9/F) | F | F4 A4 B♭4 C5 D5 | 7/4/3 | 9 st, 124 mm | | Third inversion (B♭maj9/A) | A | A4 B♭4 C5 D5 F5 | 7/4/2 | 8 st, 110 mm | | Fourth inversion (B♭maj9/C) | C | C4 D4 F4 A4 B♭4 | 9/7/5 | 10 st, 138 mm | ## Voicings (11) | Voicing | Notes | Span | Relation | Omits or adds | | --- | --- | --- | --- | --- | | Close, root position | B♭3 D4 F4 A4 C5 | 14 st, 193 mm | identical | none | | Close, first inversion | D4 F4 A4 B♭4 C5 | 10 st, 138 mm | identical | none | | Close, second inversion | F4 A4 B♭4 C5 D5 | 9 st, 124 mm | identical | none | | Close, third inversion | A4 B♭4 C5 D5 F5 | 8 st, 110 mm | identical | none | | Close, fourth inversion | C4 D4 F4 A4 B♭4 | 10 st, 138 mm | identical | none | | Drop 2 | A3 B♭3 D4 F4 C5 | 15 st, 206 mm | identical | none | | Drop 3 | F3 B♭3 D4 A4 C5 | 19 st, 261 mm | identical | none | | Drop 2 and 4 | D3 A3 B♭3 F4 C5 | 22 st, 303 mm | identical | none | | Shell, root 9 3 | B♭2 C4 D4 | 16 st, 220 mm | subset | omits F | | Guide tones, 3 and 9 | D4 C5 | 10 st, 138 mm | subset | omits B♭ and F | | Rootless close | D4 F4 A4 C5 | 10 st, 138 mm | subset | omits B♭ | ## One-edit neighbors | Becomes | Edit | Changes | Common tones | | --- | --- | --- | --- | | B♭maj7 | 1 3 5 7 | drops C | 4 | | B♭add9 | 1 3 5 9 | drops A | 4 | | B♭9 | 1 3 5 ♭7 9 | A becomes A♭ | 4 | | B♭7 | 1 3 5 ♭7 | A, C becomes A♭ | 3 | | B♭mMaj7 | 1 ♭3 5 7 | D, C becomes D♭ | 3 | | B♭6 | 1 3 5 6 | A, C becomes G | 3 | | B♭m9 | 1 ♭3 5 ♭7 9 | D, A becomes D♭, A♭ | 3 | ## Set theory - Absolute pitch classes: {10, 2, 5, 9, 0} - Relative pitch classes: [0, 4, 7, 11, 2] - Normal order: [9, 10, 0, 2, 5] - Prime form: (01358) - Forte number: not claimed for this cardinality - Interval vector: <122230> ## Frequencies (close root position) | Note | MIDI | Frequency | | --- | --- | --- | | B♭3 | 58 | 233.08 Hz | | D4 | 62 | 293.66 Hz | | F4 | 65 | 349.23 Hz | | A4 | 69 | 440.00 Hz | | C5 | 72 | 523.25 Hz | ## Questions and answers ### What notes are in B♭maj9? B♭maj9 contains B♭, D, F, A and C. The formula is 1, 3, 5, 7, 9. ### How do you play B♭maj9 on piano? Play B♭, D, F, A and C together. Right hand fingers 1, 2, 3, 4, 5; left hand 5, 4, 3, 2, 1. B♭ is a black key; D, F, A and C are white. ### What are the inversions of B♭maj9? 5 positions: root position B♭ D F A C, B♭maj9/D, B♭maj9/F, B♭maj9/A, B♭maj9/C. ### What is the difference between B♭maj9 and B♭maj7? Drops C. 4 of the notes are shared. ### What is an easy B♭maj9 for small hands? The close, third inversion voicing, A4 B♭4 C5 D5 F5, spans 8 semitones or about 110 mm. ### What are the frequencies of B♭maj9? From B♭3 at A440 in 12-TET: 233.08, 293.66, 349.23, 440.00, 523.25 Hz. ### What is the set class of B♭maj9? Prime form (01358), interval vector <122230>. ### How do I transpose B♭maj9 to another key? Keep the 1, 3, 5, 7, 9 formula on the new root. Cmaj9 is C, E, G, B, D; C♯maj9 is C♯, E♯, G♯, B♯, D♯. ### Is A♯maj9 the same as B♭maj9? Enharmonically yes: the same piano keys and the same sound, spelled differently. ## Provenance Every derived value above is computed by the piano.org theory kernel from the root, the quality and the stated parameters. Nothing is hand-entered per chord. Machine record: https://piano.org/api/knowledge/v1/entities/chord:major-9th:b-flat Last reviewed: 2026-08-12