Can someone tell me what it means when you see a chord like fadd9. What does the add9 mean?

Thank You, Brad

In the key of F, the scale tones are numbered:

1 - F
2 - G
3 - A
4 - Bb
5 - C
6 - D
7 - E
8 - F
9 - G

etc

Normally an F major chord would be 1, 3, 5 - F,A,C

Add 9 means play 1, 3, 5, 9 - F, A, C, G - where G is the ninth.

When you see F9 (without the "add") the dominant seventh is implied so you play a b7 (flattened seventh) as well (in the F scale this is Eb) - 1, 3, 5, b7, 9 - F, A, C, Eb, G...

Mel is correct.

Note that BIAB does not support entering a chord type of "add9" so you have to use "2". For example, to get Fadd9, type F2.

Explanation: you can always subtract the number 7 from a scale tone that is higher than an octave and get the same pitch an octave lower, so 9 - 7 = 2. Both are the note G in the key of F major. You get the same pitches as an add9, just in a different inversion. Styles take care of the voicing automatically.

To see possible chord types allowed in BIAB, right-click and select Chord Builder. Many are listed in the 'Other' dropdown list.