The 9th's color — add9 and m9

This week is where the tinting begins. Onto the Dm9 → G13 vamp you got last week, from today we drop tension — a splash of color — one drop at a time. The first color is the 9th. Just laying on a single 9th makes a flat chord bloom soft and round. add9 adds only the 9th to a triad; m9 adds the 9th to a 7th chord (with the b7) — the same 9th, but held in a different vessel.

In D minor, the 9th is E. Dm(add9) rings just R, b3, and the 9 — a clear sound. Add the b7 (C) and it becomes Dm9 at once. The moment the b7 enters, the sound grows deeper and jazzier. Remember with hand and ear that the difference between the two chords is exactly one b7.

Today's goal is simple. To tell the 9th's color of add9 and m9 apart by ear. No speed needed. Ring the two chords slowly in turn, and listen separately for the soft color the 9th makes and the depth the b7 adds. So first, let's lay the Dm(add9) grip on the hand.

▶ Dm(add9) — only R, b3, and the 9 ring. It's a triad plus the 9th, with no b7.

Now add the b7 on top and tint it into Dm9. You only lay one more finger (3rd string, 5th fret), yet the depth of the sound changes completely. The 9th (E) stays put; you're just filling in the b7.

▶ Dm9 = Dm(add9) with just the b7 (3rd string, 5th fret) added.

Let's hear the two chords side by side. Bar 1 is add9, bar 2 is m9 — the 9th stays, only the b7 comes and goes.

▶ BPM 70. Bar 1 add9, bar 2 adds the b7 to make m9. The 9th (E) stays alive in both bars.

0–10 min · Warm-up BPM 60. Warm your hand by grabbing Dm(add9) and Dm9 in turn. Get the feel of one finger on the 3rd string going in and out into your body.

10–20 min · Brain training (telling the 9th's color apart) With the left hand only, silently move between the two chords. Check with your eyes first: the difference of having the b7 (3rd string) or not.

20–40 min · Real color drill (BPM 70) Repeat the four bars below, moving add9 → m9 twice. Chase by ear the moment the b7's depth spreads over the 9th's soft color.

▶ BPM 70. Move add9 → m9 twice and hear how the 9th's color deepens.

40–50 min · Recording / self-feedback (recommended) Record 30 seconds and listen back. Check whether add9 and m9 sound like different colors.

Done when: You can ring Dm(add9) and Dm9 in turn and tell the 9th's color difference apart by ear.

Here are just the mistakes that show up most when handling the 9th.

▶ The 9th (E) is the 2nd string, 5th fret — one octave and one step above the root.

• The 9th gets buried. The 2nd string 5th fret must ring clearly for the color to come out. Stand the finger up slightly so other strings don't cover it.
• It's add9 but the b7 sneaks in. Mute the 3rd string firmly to get the pure add9 sound.
• The two chords sound the same. Drop the BPM to 55, ring one chord at a time long, and open your ears.
• Your hand hurts. If force piles onto the pinky (2nd string), lower the wrist a touch to share the weight.