Progressive rock music is a sub-genre of rock, and it first emerged in the 
1960s. People were sceptical at first, but soon enough they learned how to appreciate the diversities the sub-genre has. Nowadays, many people love the music, and it has become widespread around the globe. If you are wondering what makes the difference between progressive rock and the original rock music, here are the few outstanding modifications.
Lyrical Content
Unlike rock music which mainly targeted teenagers, progressive rock targets a more ‘mature’ audience. Rock was well known for themes such as love, rebellion, dancing and anti-adulthood. Progressive rock deviates from this trend, and most of the lyrics are composed of issues faced by society. Topics that can be considered intellectual such as folklore, psychology and classical literature are common. Therefore, by listening to the contents of a song, it is easy to tell whether it is rock or progressive rock.
Instruments
Musicians who write progressive rock love to experiment with the 
instruments they intend to use. At times, the musicians may decide to change the functionality of a device to bring out a new melody. Traditionally, progressive rock musicians were the first to promote the use of the bass as not only a rhythm setter but also a lead instrument. Coincidentally, progressive rock emerged as music equipment was being advanced. Therefore, instead of using an orchestra each time a band needed to perform or record music, they would use taped records of the instruments they wished to integrate with the tunes.
Music Form
Traditionally, songs followed a specific structure. There had to be verses, a chorus and the standard time for a single song was three minutes. Progressive rock tended to deviate from that norm, and their songs often had a lifespan longer than three minutes. Bridges that separate verses in the songs were introduced. This transformation allowed for more content to be placed in a single song.