Hi. When looking at chords there are letters that I don’t understand. U and TT are the main ones. I assume m3 or M3 mean minor/Major 3rd. P is perfect, A is augmented, d is diminished. Thanks.

# Annotation Question

**desunit1**#2

Hi,

Thanks for your question! I’ve just created a new FAQ topic for that:

Hope that helps!

**labadien**#3

Can you explain why your tool uses a zero 0 as the first index of the list, it seems like it should be 1, but there must be a reason you start counting with a Zero on the root note in red. Thanks for any help.

**desunit1**#4

Hi,

Check out this wikipedia article below. Basically it’s P1 or Unison semitone interval.

Hope this helps!