Open your preferred music production software program -- for example Logic, Cubase or Pro Tools.
Click "File" and select "Open New." This opens a blank session.
Click "File" and select "New MIDI Track." A MIDI track is distinct from an audio track in that it receives note and velocity data, rather than sound data. A note played with a MIDI instrument is called a "MIDI event." You can edit the pitch, length, tone and timbre of a MIDI event after you record it.
Click on "Instruments." Select a monophonic synthesizer, such as Logic's "ES2" synthesizer. If you find a polyphonic synthesizer that you like the sound of, there is no reason why you shouldn't use it, provided you play only one note at a time when recording. 8-bit music is characterized by monophonic synthesizer sounds, and to use polyphonic sounds would be inauthentic.
Click on the "Arrange" tab to open the relevant window. Typically, music production programs have a window for song arrangement and a window for mixing.
Open the step editor window. The method for doing this varies according to which program you are using, but typically you need only click a tab. For example, in Logic click "Window" and select "Step Input Keyboard."
Click "Arpeggio" on the step editor keyboard interface and select "Run." Type in the number of repeats you want each note arpeggio to sequence before it dies off.
Type in your preferred tempo at the bottom of the screen. The default beats per minute, or "BPM," setting is 120. Change this to a minimum of 200 BPM as a starting point. 8-bit music is typically at least 200 BPM.
Key in a melodic sequence of notes into the step editor grid interface. The horizontal axis represents time in beats and measures. The vertical axis represents pitch. Only put one note on any given vertical column; otherwise, that particular beat becomes polyphonic. Once you've completed four measures worth of notes, click "Copy" on the top of the editor.
Minimize the step editor. Right-click on the blank MIDI track and select "Paste" to export the loop into the "Arrange" window.
Maximize the step editor. Click on "Instruments" and select an electronic drum kit from the drop-down menu. Use the step editor to program a drum beat in the same manner as you programmed the melody. Note: When drums are selected, the vertical axis represents different drums rather than different pitches of the same sound. Once complete, paste into "Arrange" window.