Question (to Chuck)

What is the difference between a C2 and a Cadd9?

I can tell you when I play a C2 I generally do not play the 3rd. IE I woulc play C,D and G.

I'm also very curious about Suspended chords. I have seen for a long time chords like Csus or Asus then when I was using a software package and tried to enter Asus as the chord name it errored and sais Asus was not a valid chord and it gave me a l;ist of valid chords to choose from and Asus4 was there. I was wanting to play the 4th note in the scale so I choose Asus4. So what's the deal with that? Whats the diff between Asus and Asus4. Or does Asus imply the 4th?

Thanks in advance.

Bob
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