Sound travels as longitudinal waves. The particles in the substance bounce backwards and forwards along the line as in the slinky demo .

The speed of sound varies depending on the material that the sound travels through.  Generally the denser the material the faster the speed of sound in that material. If there are no particles  then sound cannot travel. this is demonstrated when a bell is put in a vacuum.

Although the speed of sound in a particular substance is fixed, the rate at which the particles can vibrate backwards and forwards and the size of these vibrations affect the sound.  the faster the particles vibrate backwards and forwards the greater the frequency of the sound and the higher the pitch of the note. The greater the size or amplitude of the vibration the louder the sound.

Another example of this is a guitar string.  As it moves from side to side it compresses the air so creating sound

As the string is tightened the pitch or frequency increases.  As the string is loosened it goes down

If an object is caused to vibrate at a specific frequency it can resonate. Here are several examples of this. the first is a square plate of metal. this shows how sound can cause some pretty patterns.

If the power is turned up, sound can break a wine glass

A jet fighter breaking the sound barrier can also be particularly spectacular

If the resonant frequency is just right it can break bridges as was shown in November 1940 at Tacoma Narrows where the wind blew at just the right frequency to get the bridge moving.  It was affectionately known as “Galloping Gertie”