Voltage control defines the synthesizer and differentiates it from separate components such as amplifiers, oscillators, filters, etc.<ref>'''[https://books.google.co.uk/books?id=c1NBTlBMDyYC&lpg=PA115&ots=FfBDaX6_QI&pg=PA115#v=onepage&q&f=false Vladimir Ussachevsky: A Bio-bibliography]''' by Ralph Hartsock, Carl John Rahkonen, Greenwood Press, 2000, ISBN
The synthesizer generates and modifies electronic waveforms in the audio spectrum. Unlike traditional acoustic instruments such as violin, percussion, etc., the electronic medium is highly flexible. Instead of physically altering the material of typical instruments, such as bracing a guitar to change its resonance, synthesizers can only need to change electrical or digital values to make new sounds. This makes them much more fluent than traditional acoustic instruments. It also means they can create sounds that aren't physically possible. Finally, players can explore the variety of sounds much more quickly and easily.