You can tell if it is in tune with itself, but not if it is in tune PERIOD. You need either a tuning fork or a basic guitar tuner.
If you hit the resonant frequency, yes it will.
The guitarist will be turning chemical energy from food eaten into mechanical energy - the movement of his arm, the impact on the string. The string will begin to vibrate, another form of mechanical energy. The vibrating string will cause the air to vibrate too, causing the sound that we hear from the guitar which is another example of mechanical energy.
A Dpad is a button on a guitar that can be used as strumming. (Does not substitute for string strumming.)
My guitar teacher told me the basics of strumming and picking.
Strumming into the Future: The Resonance of Guitar Online
guitar
tonto!
The strings on the guitar vibrate producing noise, not the actual guitar itself.
Strumming / fingerpicking / tapping, and more.
Both guitars and pianos have strings. Striking the strings causes them to vibrate, which makes the sound that you hear.
Learn some basic chords and practice strumming. Listen to rhythm guitar parts and try to figure out what strumming pattern they're using. Then practice. Once you get your strumming hand going don't stop.
When you push the white bar on the body of the guitar up or down. Each move is called a strum and on Guitar Hero guitar, each strum is accompanied by a "click" sound. Sadly there is no click sound when strumming on a Rock Band guitar.