A major add9 chord is created by adding a 9th degree to any major chord. For example, a Cadd9 chord contains the notes C, E, G and D (1, 3, 5 and 9). Here are some common open major add9 chord shapes.
Cadd9
Dbadd9
Dadd9
Ebadd9
Eadd9
Bbadd9
Gadd9
Fadd9
F#add9
Abadd9
Aadd9
Badd9