In a book of jazz trumpet duets (for Bb trumpets), I keep seeing chord symbols like "Fj" (shown below). I'm familiar with the various kinds of chord symbols (the various seventh chords, extensions, etc.), but I've never seen "j" before. What does it mean?

Chord symbol Fj

(Image Source: Wolf Escher, 20 Jazz-Duette: Heft 1, [Schott Music, 1982], page 23)


1 Answer 1


It means "major seventh". "Fj" is equivalent to "FMaj7" or "FΔ7". It is rarely used.

A clue to its meaning is given a few bars later, in the final measure of the piece. The trumpets are playing their A and E, respectively, with "Fj" indicated as the chord. E being the major seventh of F, it's clear the chord would be a major seventh chord.

Fj symbol with written A and E

An even more clear example can be found on page 20 of the same book. As shown below, there is a progression "Dm Dmj Dm7". The second trumpet plays D, Db (C#), C respective to each chord symbol. In other words, the basic chord is D minor, with the second trumpet making a chromatic decent from ^8 to ^#7 to ^7. Thus, Dmj is D minor with a major seventh, or DmM7.

Dm Dmj Dm7 progression

  • 4
    This is great, never seen "j" used.
    – John
    Oct 5, 2022 at 2:40
  • Any ideas why 'j'? I've never ever come across that one! +1.
    – Tim
    Oct 5, 2022 at 6:49
  • 1
    That's a probable. Maybe should have been followed up with 'n' for minor..?
    – Tim
    Oct 5, 2022 at 8:01
  • 2
    Anecdotical fact: if you use the "Band in a Box" program, which generates accompaniments based on a chord sheet, you can press 'j' for Maj7. Also 'h' for m7b5 (half diminished), 'o' for diminished and 's' for 7sus.
    – Jos
    Oct 5, 2022 at 9:29
  • 2
    I have seen j7 in form of this piece of documentation here lilypond.org/doc/v2.23/Documentation/snippets/… This is a reasonable step, maj7 gets shortened to j7 (since m7 would cause problems with minor chords). And from there I guess it is not unreasonable to say: Actually we only need j for j7, so we can simply leave out the 7.
    – Lazy
    Oct 5, 2022 at 11:05

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