anyone can, just you may not be famous, but anyone can sing or perform
I suppose it depends on the country they are in and the kind of music they are performing. Here in North America... they can (now) play anything they want, anytime they want.
Ellegarden was formed in Chiba, Japan in 1998. Their music style ranges from punk rock to pop punk. Unfortunately now Ellegarden is no longer together.
The genre of music in which the artist Rodney Atkins perform is country music. His music tends to be styled after a more contemporary country kind of style.
Music
They returned in the 2007 coachella music festival and ever since have been doing concerts every now and then
Selena performs Tejano music.
It is known as 'Afrobeat' music.
They do pop music with a little rock in it.
First you need to know how to play an instrument; then you can hopefully create your own music, write it, and perform it. All of these qualities are classified as a musician. Now, having a degree in music is different.
Cathy Jean performs American pop music. She started performing in the 1960s and continues performing today. She now goes by her married name, Cathy Jean Ruiz.
She did perform at the 2009 American Music Awards.
She composed Pop music