Instruments commonly used by disco musicians included the rhythm guitar (most often played in "chicken-scratch" style, usually through a wah-wah or phaser), bass, piano and electroacoustic keyboards (most important: the Fender Rhodes piano and Wurlitzer electric pianos and the Hohner Clavinet), harp, string synth, violin, viola, cello, trumpet, saxophone, trombone, clarinet, flugelhorn, French horn, tuba, English horn, oboe, flute, piccolo, and drums, African/Latin percussion, timpani, as well a drum kit. Electronic drums were making a debut during this era, with Simmons and Roland drum modules appearing as pioneers in electronic percussion. Most disco songs have a steady four-on-the-floor beat, a quaver (or occasionally semi-quaver) hi-hat pattern with an open hi-hat on the "off" beat, and a heavy, syncopated bassline.

This quaver pattern is often supported by other instruments such as the rhythm guitar (lead guitar parts are rare), and may be implied rather than explicitly present, often involving syncopation and rarely simply on the beat unless a synthesizer is used to replace the bass guitar.

The orchestral sound usually known as "disco sound" relies heavily on strings and horns playing linear phrases, in unison with the soaring, often reverberated vocals or playing instrumental fills, while electric pianos and chicken-scratch guitars create the background "pad" sound defining the harmony progression. Typically, a "wall of sound" results. There are however more minimalistic flavors of disco with reduced, transparent instrumentation, pioneered by Chic. Dramatic minor and major seventh chords and harmonies predominate in much disco.