I'm expanding my chord vocabulary these days myself. Ninth chords and "slash" chords are my faves these days.

'course, that's what happens after you've been in a Woody Mann class or two. Those first-position chords seem so vanilla!

They are standard major triad chords (1-3-5) with the 9th (2nd) tone of the scale added. Using the standard moveable C-A-G-E-D chord forms everyone learns early on, I think these adjustments will give you add9 voicings:

C form - raise 2nd string two frets

A form - drop 2nd string two frets (play open)- I remember this as the Townsend chord due to how it resolves in Behind Blue Eyes (play at end of verses such as "to telling only lies")

G form - raise third string 2 frets

E form - raise 4th string 2 frets - the Prince chord. He actually uses three add9s in Purple Rain. The verse progression is Aadd9-F#m11 (6th-2nd fret ,5th-open, 4th-2fret, 3rd-2nd fret, 2nd -open, 1st-open)-Eadd9-Dadd9 (the one with the 1st string open). FYI, as part of an acoustic set, this is a great tune for getting the bar crowd singing the chorus with you!

D form - Raise 4th string 2 frets, or drop the 1st string two frets (play open), or raise 2nd string 2 frets. You may have to barre across the bottom 3 depending on your reach on the last one.

The add9s also sound great in ii-V-I progressions as the I chords because they resolve so strongly.

Greg, please share what kind of music you're playing with them and other voicings you're using.

To answer Kurt's question, the add9 (1-3-5-9) differs from the maj9 (1-3-5-7-9) due to the 7 in the maj9. Also, the 3 is often dropped from the maj9 to retain a 4 tone chord structure. I consulted my original 1971 copy of Ted Greene's Chord Chemistry for this information and reminded myself how brilliant but intensely dense and scary that book is from a guitar music theory standpoint.

I also found a great article in the September 1998 isssue of Guitar Player called "A Connoisseur's Guide to Harmony" written by Jesse Gress. He writes about both the add9 and the slash chords mentioned in this thread in the context of developing new tasty chord progressions. The article has lots of great examples and it seems to be a good overall lesson in developing harmony in your chord choices. There are some tough finger stretches, a la Ted Greene, for those needing fingering calisthetics. Some of the add9 forms span 5 frets but are worth the effort. There's also a good simple recipe for reharmonizing a melody.

Thanks again for tweaking my curiosity on this stuff Gregory and helping me find some cool stuff to add to my chord vocabulary and arranging tool box. That what this forum is about!

1. Adding the 3 in the A form on the fifth string at the 4th fret makes the Add9 in this form sound better.

2. Very cool sounding use of MinorAdd9 in ii-V-I progressions. To get the minor in each of the C-A-G-E-D forms, flat the 3 tone as follows:

C form - drop the 4th string down a fret

A form - drop the 5th string described above down a fret

G form - drop the 5th string down a fret

E form - drop 3rd string down a fret

D form - on form with 4th string root raised 2 frets for 9, drop 1st string 1 fret

Check out combining these in a ii-V-I progression using the 1st 4 frets like:

Gmadd9 (top 4 strings)-C7-Eadd9 (C6 sounds great too)

AmAdd9-D7-GAdd9

Some very nice bass and melodic lines are naturally created with this stuff!