Add a second sound card to your computer. You will need to be able to loop the output from your synthesizer program back into the recording input on your sequencer so you can record loops and patterns to add to your track. You will then need to be able to loop the output from your finished track in the sequencer back into the input of your recording software for final edits and conversion to CD Audio or MP3.
Install a MIDI keyboard to your computer. You can actually create music with your computer keyboard or by point and click with your mouse, but adding a MIDI keyboard will cut production time significantly by allowing you to play along synthesizer inputs with your beats rather than having to map out each note individually.
Install your software programs. You will need a sequencer, such as Fruity Loops, to create beats and arrange your music tracks. You will need a synthesizer program, such as Reason, for adding and even creating synthesizer sounds to your beats. Finally, you will need a recording program such as Pro Tools, Sonar or Cubase for adding effects and recording vocals if you choose.
Create beats for your track. Sequncer programs allow you to create several beat patterns and then arrange them in a layout to form the beats for your complete song. This allows you to have verses, choruses, bridges and breakdowns, and any other beat variations you may wish as you create your track. You can also import custom percussion sounds if you wish to add them to your beats.
Add synthesizer tracks. While playing patterns on your MIDI keyboard through your synthesizer software, you can record short clips into your sequencer, and arrange the sound patterns with the beats in the layout to create a full song.
Import your music track into your recording program, and lay down vocals or add effects. Your music will record as a single track, so make sure you are done editing that portion before you record from your sequencer program into the recording program. Vocals can then be laid as a separate track so you can balance the levels before saving the song in CD Audio or MP3 format.