Quote:

C2 us an abbreviation for the Csus2 chord.






In BiaB, C2 also stands in for Cadd9, which is a completely different chord.

The add9 has an E in it. A C2 does not.

And I wish BiaB would name chords the way probably 99% of the (non jazz) guitarists out there do.

A chord replacing the third with the second, is a Csus2.

A chord replacing the third with the fourth is a Csus4.