Form: Progressive rock songs either avoid common popular music song structures of verse-chorus-bridge, or blur the formal distinctions by extending sections or inserting musical interludes, often with exaggerated dynamics to heighten contrast between sections. Classical forms are often inserted or substituted, sometimes yielding entire suites, building on the traditional medleys of earlier rock bands. Progressive rock songs also often have extended instrumental passages, marrying the classical solo tradition with the improvisational traditions of jazz and psychedelic rock. All of these tend to add length to progressive rock songs, which may last longer than twenty minutes.

Timbre (instrumentation and tone color): Early progressive rock groups expanded the timbral palette of the then-traditional rock instrumentation of guitar, organ, bass, and drums by adding instruments more typical of jazz or folk music, such as flute, saxophone and violin, and more often than not used electronic keyboards, synthesizers, and electronic effects. Some instruments – most notably the Moog synthesizer and the Mellotron – have become closely associated with the genre.

Rhythm: Drawing on their classical, jazz, folk and experimental influences, progressive rock artists are more likely to explore time signatures other than 4/4 and tempo changes. Progressive rock generally tends to be freer in its rhythmic approach than other forms of rock music. The approach taken varies, depending on the band, but may range from regular beats to irregular or complex Time Signatures.

Melody and Harmony: In prog rock, the blues inflections of mainstream rock are often supplanted by jazz and classical influences. Melodies are more likely to be modal than based on the pentatonic scale, and are more likely to comprise longer, developing passages than short, catchy ones. Chords and chord progressions may be augmented with 6ths, 7ths, 9ths, and compound intervals; and the I-IV-V progression is much less common. Allusions to, or even direct quotes from, well-known classical themes are common. Some bands have used atonal or dissonant harmonies, and a few have even worked with rudimentary serialism.

Texture and imagery: Ambient soundscapes and theatrical elements may be used to describe scenes, events or other aspects of the concept. For example, Leitmotif is used to represent the various characters in Genesis' "Harold the Barrel" and "Robbery, Assault and Battery." More literally, the sounds of clocks and cash registers are used to represent time and money in Pink Floyd's The Dark Side of the Moon.

BaldFriede wrote: As to the lyrics: Sorry, I don't know what the majority of prog lyrics consist of. Please enlighten me.