In Byzantium organs remained in the royal courts and palaces, they did not get a place in Christian liturgy. Western Christianity started to apply it. It had an equal role with singers in the liturgy in introducing hymns but never along with the singers because of its technical characteristics. Early but not standardized organ manuscripts show that the instrument mostly took over the sung part of the liturgy, in the Roman Catholic tradition for example it was used to replace the singing of the congregation, so the organ played the psalm, antiphon or hymn alternating with the choir. In other cases it filled the liturgical vacancies, e.g. under the entrée or communion. Basically improvised instrumental music was suitable for that.
In 1312 in Venice a German master built the first great church organ which was followed by an increasing number of instruments. These started to resemble more and more their present day followers. In the 15th century the pedal appeared and among the white (ivory) keys you could discover the black (ebony) ones. The builders made special new parts (works) for the organ to perform popular multiple-voice chorus pieces, this way making it possible to clearly distinguish the different voices. Various tone qualities became available and the groups of colours could be contrasted after each other. By developing the pedal, the more and more important bass voice could be emphasized. The keyboards were placed close to each other in order that one organist would be able to play on them. A particular innovation of that time was the combination of two manual divisions under each other in one organ. Then the road to the ‘classic’ three-manual and pedal organ was shortened.
While the Roman Catholic Church was becoming free in decorating the liturgy with the use of the organ, the Calvinists insisted on their God-given right to recite the fixed texts. From the Genevan churches they even expelled organs. The Lutherans nurtured mixed feelings towards this instrument. In the beginning they banned it from certain parts of the liturgy but later they accepted it because it ensured continuity and provided space for mediation. Organists gained bigger and bigger reputation so much as it was in the Lutheran church where concert organ music was born.