Things You’ll Need:
* Either a real piano keyboard or a simple mock up of one
* Knowledge of the basic note scale and where those notes exist on the keyboard
If you are not familiar with the basic note scale and where it exists on the piano keyboard, just look it up on the Internet or have someone knowledgeable about the scale show you.
Once you know the basic note scale, write the scale down across the top of a sheet of paper, beginning with “C” and leaving a little space between each of the remaining notes.
Write the number “1″ above the letter “C,” the number “2″ above the letter “D” and so on across the scale. Once completed, you now have the core of the Number System in front of you. In the studio, if the players were preparing a “chart” for a song in the key of C, and the first, say, five chords to be played in the song were C, F, G, F, G, the “chart” would simply read 1-4-5-4-5.
The final step is what makes the number system so user friendly. Unlike conventional sheet music which has to be re-written for each key that the song needs to be played in, with the number system, you change keys simply by assigning the number 1 to the key of the song and then numbering the other notes accordingly. So, if the song is in the key of G, the G note in number 1 and so on.
Link to Original Article:
How To Learn the Nashville Studio Number System | eHow.com