Genres

Pink Floyd was considered one of the first psychedelic music groups. According to Rolling Stone: "By 1967, they had developed an unmistakably psychedelic sound, performing long, loud suitelike compositions that touched on hard rock, blues, country, and folk."

By the late 1960s, the press had begun to label their music progressive rock.

 Pink Floyd were innovators of progressive rock during the 1970s and ambient music during the 1980s.

Psychedelic Rock

Electric guitars, often used with feedback, wah wah and fuzzboxes

Elaborate studio effects, such as backwards tapes, panning, phasing, long delay loops, and extreme reverb

Exotic instrumentation, with a particular fondness for the sitar and tabla

A strong keyboard presence, especially organs, harpsichords, or the Mellotron (an early tape-driven 'sampler')

Extended instrumental solos or jams

Complex song structures, key and time signature changes, modal melodies and drones;

Primitive electronic instruments such as synthesizers and the theremin

Lyrics that made direct or indirect reference to drugs, as in Jefferson Airplane's "White Rabbit" or Jimi Hendrix's "Purple Haze"

Surreal, whimsical, esoterically or literary-inspired, lyrics

Space Rock

Characterised by slow, lengthy instrumental passages dominated by electronic organs, synthesizers, experimental guitar work and science fiction or astronomical lyrical themes.

Folk Music

It was transmitted through an oral tradition.

The music was often related to national culture. 

The songs have been performed, by custom, over a long period of time, usually several generations.

As a side-effect, the following characteristics are sometimes present:

There is no copyright on the songs.

Fusion of cultures

Non-commercial.

Blues

Specific lyrics, bass lines, chord progressions and instruments.

Hard Rock

It is typified by a heavy use of distorted electric guitars, bass guitar, drums, and often accompanied with pianos and keyboards.

Progressive Rock

Tempo, key and time signature changes are very common in progressive rock.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 complex time signatures.

The genre abandoned many of rock's traditional characteristics, including a standard verse-chorus structure, and often replaced the electric guitar with more layered and complex instrumentation to create longer compositions.

Progressive rock bands tend to avoid typical rock/pop subjects such as love, dancing, etc. Unlike other rock genres, they also deliberately avoid typical themes appealing to youth such as sex, violence, nihilism, rebellion, and the macabre., rather inclining towards the kinds of themes found in classical literature, fantasy, science fiction, folklore, social commentary or all of these.

Use of the synthesizer