Rock Music is probably the most popular genre of all the 1960 - now if not of all time, It was developed from the roots of Rock and Roll and is changing/developing in every way. A Rock song is most commonly based on a 4/4 beat while rhythm keeps to itself on top. Rock music has had a huge impact on peoples daily lives while staying on top. The most common instruments you would see at a Rock Show/ Stage: Guitars whether Acoustic or Electric, Bass Guitar, Keyboards (optionally), Drum Kit, and Of Course Microphones for Vocals, There are other Rock bands who like to experiment on different instruments and using them for regular use e.g. Different choice of guitars such as classical, acoustic and Double necked, More keyboards for experimentation e.g Bass Pedals, Additional Keyboards or Piano For A quick change, Drum players are the most common to see a change to their Drum Kits e.g More Cymbals and Tom Toms, or by using additional percussion objects such as Cowbells, Wind chimes, Temple Blocks, etc. While Rock Music had a Different sound inspiration as time went by there was an impact on what kind of fans had listened to the music. The 60's was the main developing stage of rock and with Groups like The Beatles and The Who were springing onto the future of Music.
And the 70's had a much broader audience of Fans springing onto a heavier/classic period of Rock with Famous Groups such as Led Zeppelin, Boston and Rush.
When Simply heavy guitar music had declined slightly in the 1980's, people wanted a change into their sounds. This was when Synthesisers were a major part onto Rock Music, Groups like Simple Minds, Rush (They change their different ways of music mostly every Album) and Icehouse had a main duelling offspring of Guitars and Keyboards.
The Synth declined in the 90s and Alternative/Garage Rock was the answer, A Chunky Raw Distortion Driving Teenagers insane with examples such as Nirvana, Alice in Chains and Sonic Youth are...