Unaccompanied church music sung in unison and in free rhythm according to the accentuation of the words.
                                                            
                                                     
                        
                                                
                        
                        
                            6th century single line vocal melody, still used in Roman Catholic ceremonies.
                                                            
                                                     
                        
                                                
                        
                        
                            a liturgical chant of the Roman Catholic Church 
                                                            
                                                     
                        
                                                
                        
                        
                            common designation for Gregorian chant
                                                            
                                                     
                        
                                                
                        
                        
                            Liturgical chant, such as Gregorian chant.
                                                            
                                                     
                        
                                                
                        
                        
                            a type of religious music with roots in the Medieval church, like the alabados it uses modes and lacks time signatures.
                                                            
                                                     
                        
                                                
                        
                        
                            monophonic chant which is unmeasured, and unaccompanied; such as gregorian chant.
                                                            
                                                     
                        
                                                
                        
                        
                            Broadly speaking, plainsong (also known as plainchant) is the name given to the body of traditional songs used in the liturgies of the Roman Catholic Church. The liturgies of the Eastern Orthodox Church, though in many ways similar, are generally not classified as plainsong, though the musical form is nearly as old as Christendom itself. Plainsong is also commonly used in the Anglican churches.