A common technique in much modern electronic music is to use arpeggios of various sorts, deriving from the use of automatic arpeggiators and pattern-sequencing devices. Many synthesizers have an abundance of arpeggio patterns preprogrammed and ready for use. In such cases, it is simply a matter of selecting the pattern you require and sequencing. However, dependence upon such preprogrammed patterns can be limiting, and sooner or later you will want to produce your own patterns. This chapter will show you some of the principles behind this concept.