With records dating back to 1312, the Chapel Royal is a group of singers that are appointed to sing for the country's reigning sovereign.  They would travel wherever the monarch was living at the time, and was originally created for religious, or spiritual purposes.  It is said that the chapel acheived its greatest height during the reign of Elizabeth I because of William Byrd and Thomas Tallis both being members.  Eventually, the name came to encompass the building that they used.  It is still used today. Image source: Wikipedia