A musician is a person who composes and/or performs music, usually as an occupation but often as a hobby. He or she may play a musical instrument or several musical instruments, or he or she may be a vocalist instead. A person who makes his or her living as a musician must usually spend a significant amount of time learning how to play an instrument or sing exceptionally well to become known within the music world, which is a highly competitive field in which failure is not only possible, but exceptionally likely.
Any genre of music can be played by a musician. He or she may focus on one specific genre — rock and roll, for example — or the musician may be talented enough to write and perform music across a wide range of genres. Many genres of music are closely related, making it easier for a musician to perform in more than one genre, though it will still take some talent to perform or write music well in more than one genre.
Musicians who make their living off writing or performing music do not often make a significant amount of money. The lifestyle can be particularly difficult, as many musicians travel constantly to expose their music to a wider range of listeners. The musician may produce a music album for sale or for exposure, but live performances are more likely to help the musician gain notoriety. Some musicians get noticed by record company representatives, who subsequently sign those musicians to record deals. These deals can vary in details, though many allow the musicians to create and distribute a music album; sometimes the deal allows them to tour around a region or country, or even the world, to promote the album and the musicians themselves.
A band is a group of musicians who play music together. Bands usually consist of several musicians who play different instruments, and the band usually focuses on one genre. Some mix genres as well, though again, this can be difficult to do well. A rock band, for example, may feature members who play drums, guitars, bass, and piano or keyboards. The band will also likely feature one or more vocalists. That rock band may focus on a certain genre of music, namely rock and roll, though they may incorporate elements from other genres, including the blues, jazz, folk, funk, and so on. Bands tend to develop a certain style by combining elements of different genres of music.