A Choir is a company of singers, especially an organized group employed in church service. any group of musicians or musical instruments; a musical company, or band, or a division of one: string choir.

Choirs are also categorized by the institutions in which they operate:

• Church (including cathedral) choirs.
• Chorale (Kantorei), dedicated to mostly sacred Christian music.
• Collegiate and university choir.
• Community choir (of children or adults)
• Professional choir, either independent (e.g. Anúna, The Sixteen) or state-supported (e.g., BBC Singers, National Chamber Choir of Ireland, Canadian …
• School choirs.
• Signing choir using sign language rather than voices.
• Integrated signing and singing choir, using both sign language and voices and led by both a signductor and a musical director.