Voice
A singer is a person who sings. Anyone who is singing is a singer. Some people do it as a job (professional singer), others may sing without being paid (amateur singer). Singers may sing anything: song, opera, etc. They may be accompanied by an instrument or an orhchestra. Some singers also play a musical instrument such as piano, guitar or harp while they sing (they accompany themselves).
Singers can sing as a solo, or in a group or a choir. Choirs can include gospel, church music and even pop songs where there are usually two groups of singers, soprano and alto. Sopranos have a higher range and altos have a lower range. Combining these two can create various harmonies which add textures to songs and make them more interesting to listen to.
People may want to sing for a variety of reasons. They may wish to express their emotions to others. They could be happy, sad, excited, frustrated, or angry about something. Singing is an art form in which the voice expresses mood.