A rock band is a group of musicians who play rock music together. Rock is an extremely diverse genre, encompassing a range of styles and sounds, but it is typically based around guitars, bass, drums and vocals.
The roots of rock music lie in blues and country, but the genre has taken on many other influences as it has progressed, including jazz, folk, classical and electronic music. Today, rock encompasses styles as diverse as punk, metal, indie rock and noise rock, and many bands incorporate elements of numerous styles.
Rock music typically centers around the electric guitar, which provides much of the melody for songs. Most rock songs are in standard 4/4 time and employ a traditional verse-chorus structure, in which a verse leads into a prominent chorus, which is the most melodic and memorable part of a song. However, many rock bands break away from these conventions, utilizing varied instrumentation, unusual time signatures and unconventional song structures.
The majority of rock bands feature guitars, bass, drums and vocals, though other instruments, such as keyboards or saxophone are also common. Bass and drums provide the rhythm of a song, while guitars are often used as lead instruments, creating additional melodies and used for performing solos. Many bands feature a lead guitarist, who performs more elaborate guitar parts and solos, and a rhythm guitarist, who performs simpler rhythmic guitar parts and often sings lead vocals as well.