You can change the tone and attack of the strum by changing how tight your fingers holding on to the pic and the angle you use when striking the strings, etc......
Make a D chord, then experiment with how many different tones you can get from the D chord changing how you strike with the tool.
Hand a guitar to 5 different people and have them play the same thing, somehow the guitar sounds slightly different as each player plays. Nothing about the guitar has changed, its the different technique each person uses when they strike the strings.
