I received a question on keeping in tempo when playing songs. So, for this post, I will suggest a few ways that you can do so. First off, I need to state that there is a difference between beats and tempo.
Beats - Every song is played in some sort of beat. The more common one nowadays would be the 4/4 beat. What this means is that there are 4 beats in 1 bar. So, if you were to count, it would be something like "1,2,3,4, 1,2,3,4" and so on.
Tempo - The tempo of the song, determines how fast you count the beat. In music, it is called "beats per minute" or in short bpm. So, for a slow song, you would expect a low bpm count (eg. 50?) and for a fast song, you could expect a high bpm count (eg. 150?).
With that background, here are some ways you can achieve maintaining the right tempo throughout a song.
Use a Metronome
I think most pianists would be familiar with this. What is a metronome? Well, here's an example of what a metronome looks like.
The metronome is a device that basically gives you a beat.
From the little that I know, the metal strip in the middle swings left and right and each time the metal strip reaches each end, a "tick" sound is produced.
How fast or how slow the "tick" sound occurs would depend on where you place the thick metal piece (I have no idea what it is called) that is on the metal strip.
Notice the numbers on the metronome? Placing the "thick metal piece" over the desired number will give you the desired "beats per minute".
So, with the metronome, you can now achieve a constant beat effect which will hopefully help you to maintain the beat and tempo of the song, throughout the song.
Use an Online Metronome
With the wonders of technology, you can now achieve this metronome effect on your computer, and on your handphone too! Please click here for an example of an online metronome.
So, now that you are equipped with the right tools, the only question that remains is finding out the bpm of the song you are playing.
I guess the easiest way to do so would be to buy the scores of the song. This is because the score will probably mention the bpm. However, the free alternative would just be to play the song over Youtube, and to play the metronome, and find the right bpm that matches the song.
So there you go, the secret of maintaining the tempo and beat of a song!