Go to the Tu Cows website (see Resources) and click the link that says "Download Now." You will download the Fruity Loops Version 8.0.2 program, which is one of the most popular and easy-to-use beat programs.
Install Fruity Loops and restart your computer. Double-click on the shortcut and load the program.
Click the icon that has 4 squares directly under "Click to Enable Online News." Click on the squares next to "Kick" to create a bass pattern that you want. Click the Play button icon on the top of the screen to play the sequence that you have just created.
Click the browser icon next to the piano keys icon, and browse for bass sounds if you do not like the default kick sound. Drag the sound to the beat sequence window, and then make a sequence by clicking or un-clicking the boxes.
Click the piano keys icon to set the pitch of each note. Click anywhere along the piano to pick the key of the song you want. Drag the box to elongate the beat for a particular measure.