Many electronic music artists (music made with computers or other electronic instruments) use computer software to make new music parts, called "tracks". The music parts contain notes which are arranged with a computer program called a sequencer. The actual notes are played by instruments, usually synthesizers, a type of electronic musical instrument that makes sounds by changing the shape of a sound wave. It is also possible for a remixer to use a drum sample kit, a set of sounds of fake or real drums recorded for use on a computer.