This progression was made popular in the 70s in Barry Manilow’s song, “Can’t Smile Without You”. In it, the third note of a chord is altered by starting with the suspended 4th, then resolving to the major chord, then changing to a suspended second, and resolving again with the major chord. Try it in the following examples:

Dsus-D-D2-D

Dsus-D-D2-D

Listen to this progression in the key of D:

Asus-A-A2-A

Asus-A-A2-A

Listen to this progression in the key of A: