The page below is high ranked in Google for a search “music tempo,” one behind Wikipedia.org, which is a tremendous status to have achieved. You can visit The Music Lab at the link above or below.

The Music Lab – What’s Tempo?

Tempo is the speed of music. It’s a steady constant pulse, like a clock ticking. Tempo can be slow or fast or in-between, and it can change during a song. …
http://www.sfskids.org/templates/musicLabF.asp?pageid=11 – 15k -

After you get the latest version of Flash, you’ll be able to play around with Tempo!

Tempo is the speed of music. It’s a steady constant pulse, like a clock ticking. Tempo can be slow or fast or in-between, and it can change during a song. Tempo influences how music sounds and feels. The same piece of music will sound different if you play it slower or faster.

Musicians and composers often use Italian names to describe different tempos. These names say how fast or slow to play a song. When musicians want to practice at a specific tempo, they use a metronome, a machine that plays many different tempos.

In this activity, you’ll get to hear a metronone play different tempos. You select the tempo and if you want to hear it with music.